American-Machinist-May-1896-vol-2-no-9 Brown & Sharpe Machine shop Machines Gear Cutter Silver and Gay

FORGING DEPARTMENT-BILLINGS & SPENCER CO. -PAGE 210. March, 1896. MACHINERY COVER -Main Article. FORGING DEPARTMENT-BILLINGS & SPENCER CO. say-wrenches -PAGE 210.

March, 1896. MACHINERY INDEX, PAGE IV. ONE DOLLAR A -YEAR:MOTS A COPY:- VOL 2, no 7 PUBLICATION OFFICE : 411-413 PEARL STREET, NEW YORK CITY. NAP,C11. 1886 A PRACTICAL JOURNAL FOR MACHINISTS AND MECHANICS AND FOR ALL ARE INTERESTED IN MACHINE SHOP TRADES.

THE BILLINGS & SPENCER CO. The accompanying photographs, taken very recently, give an idea of the extent of the business built up by Mr. Charles E.

PRESIDENT'S OFFICE.-BILLINGS & SPENCER CO.
same time maintain true records. The prints were favorably received by the men in the shop in every case, and I never heard any man express a preference for the large scaled drawing. With this method it was impossible to scale the drawings, and the shopm en were obliged to come to the drafting-room for informa-tion, and could have no excuse for going wrong.
SECTION OF DIE VAULT-BILLINGS & SPENCER CO.
photographed on 8 X 10 plates and blue prints made from negatives, mounted on cards and shellaced in the regular way. The result was a small card drawing as clear and distinct as an engraving, readily handled for machine work or bench work. Changes could be made on the original drawing by erasing or pasting patches of new these
THE BILLINGS & SPENCER CO.
The accompanying photographs, taken very recently, give an idea of the extent of the business built up by Mr. Charles E. Billings, president of the company, who is seen at his desk in the first view. His article, which appeared in our issue of May, 18g5, gives an account of the growth of the drop forging industry, which has been largely developed by his energy and skill. The die vault, of which only a section is shown, consists of several rooms in a build-ing as nearly fire-proof as possible, and con-tains tons of tool steel, whose value mounts up into the hundred thousands of dollars. The hammer shop is well filled with drop hammers from various makers, the later ones being of their own manufacture and being exceedingly heavy in design. To one who has never witnessed the drop-forging process it is quite a revelation to walk down the long row of hammers and watch the heated metal bars assume shapes that are both intricate and interesting, and it seems almost wonderful that metal can be induced to flow into all the corners and crevices of the dies. Copper commutator bars are also forged here, and this depart-ment always presents a busy scene. The machine room is largely supplied with milling machines, mostly of the Lincoln type, while drills and " edgers " (which are really vertical mills, generally with numerous spindles) abound.

March, 1896. MACHINERY
of the T square and triangles than do the thumb tacks. They are easily withdrawn with a knife blade or small thumb tack lifter. Fig. 6 shows a neat hammer to use with them, made of 5g inch octagon steel and about 412 inches long, the point being about -,06- in. and the pene 19,- inch in diameter. This, if magnetized, can be used to pick up and to drive in tacks without the use of the figures. Fig. 7 shows a flat rule designed and used by myself which contains the scales most needed by draughts men. As seen it has the scale of 6 in. to I ft. frequently needed for detailing of small parts and yet seldom included on the engineers' scales. This section has up to the present been little used on this side of the water, though I understand it is almost universally in Europe. It is much better than the plain flat kind, both as to wear and use. Taking it in the fingers it can be easily held so that the scale is close to the paper, and being flat it does not get turned over as does the triangular when laid down, nor does it wear the edges destroying the divisions as do the latter. It must of course be made to order. As the scale of chords cannot be divided by American makers owing to lack of machines it has to be made abroad and can be obtained at very reasonable rates.* In using the scale of chords the distance from oÂ° to 60Â° is taken in the compasses and an arc described. The distance from oÂ° to the degree wanted is then laid off as a chord on this arc, giving the angle by connecting these points with the centre. It is more accurate than marking from a protractor and just as quickly done. The scale is divided into half degrees. The triangles described, I made from sheet celluloid. STRENGTH AND WEAR OF GEAR WHEEL TEETH. BELL CRANK. Several writers have presented articles on the above subject in your paper during the year, yet it seems to the writer that &me of your contributors have fully informed themselves of the avail-able knowledge extant on the subject. Joshua Rose, in his book " MACHINERY. teeth of an engaging rack. This matter of fillets is very important, and their omission will in some cases diminish the strength 15 per cent. W= working strength of tooth in pounds. s=tensile stress of material per square- inch in pounds. fi=circular pitch of teeth in inches.. f=face of teeth in inches. v=velocity at pitch line in feet per minute. n=number of teeth in wheel. For 15Â° involute and the interchangeable cycloid systems: For 200 involute: 33,00o In the interchangeable cycloid system without fillets the rack-tooth is 2.8 time3 as strong as the tooth in a twelve-tooth pinion, and a twenty-tooth wheel is almost twice the strength of the pinion. It is very obvious, therefore, that any formula for gear teeth strength which leaves out this factor, will not in many cases give any nearer the correct results than an experienced man could reach by guessing. Any one interested in the subject should get the original paper by Mr. Lewis, for the method of reaching the formula is so lucidly explained that any one with only fair mathematical ability can adapt a formula for other sys-tems or proportions of teeth than those given. I should perhaps note that the foregoing formulas will not give the breaking strength of the tooth, but are correct when S does not exceed the elastic limit of material. Some rules for strength of gear teeth are arranged to give a pitch:that_ will sustain_the desired load on one corner of the tooth. Scale of 3L--1 foot Scale of d-1 foot Inches and sixteenths Scale of chords down centre Fig. 7 Scale of foot Scala of 12 =1 foot An Machine Shop Practice," pointed out the fact that to find the actual section of a gear tooth, which is the weakest point when subject to working stress, it was necessary to consider the tooth as a beam loaded at the end, and to plot the greatest parabola that could be enclosed in the actual tooth outline. Any one who will There are of course certain conditions which will require this, but in all such cases it is useless to make the face more than one and one-half times the pitch, for any more face would seldom be in contact on a wheel liable to do most of its work on the tooth corners. It will also be perceived that any increase of face for

11xth pic down
AMERICAN MACHINIST-Section Vol. 56, No. 2 March 1896
page 200 top. Observations-in-a very old Shop ca-1860s
/ Eighth pic down
MACHINERY. March, 1896.
page 200 top
As the inventor had designed his ,engine to be run either way, both the inlet and outlet openings in the two collars at either end were on top, so the condensed water had all to be lifted or blown out, thus causing a large amount of back pressure. The inventor had previously called in the city engineer from his legitimate work on the streets and sewers-a very bright young man-who had got up a Prony-brake to test the power delivered by the engine, and put a cam on the shaft to give the necessary reciprocating motion to operate a Crosby indicator, and had taken a set of cards from different points, while obtaining the power delivered by the brake. These cards were rather curious affairs, but showed that the steam pressure actually acting on the piston was about to per cent. greater than the value of it, as delivered at the brake. They also showed, however, that the exhaust port opened while the steam was nearly at half-pressure, from which point it fell at once, rapidly, seeming to be practically used up, in the third quar-ter of the revolution, from which point the engine seemed to be carried on by the fly-wheel. I at once noticed this enormous loss of steam and decided on a different mode of operation. Retaining the friction pulley and brake, which I found, I added another arm to the brake on the opposite side, to which I attached a "hydraulic regulator," or piston working in a " dash-pot " of water, reversed the brakes, so as to lift a positive weight, instead of bearing down on a platform scale, procured a set of weights from the " City Sealer," and was ready to determine the power delivered. I saw, however, that the real point, the quantity of steam con-sumed, had not been touched; so after a day's search of all the store and repair shops in town, I found a small, cond-hand vertical tubular boiler, 3 feet long and 2 feet diameter, which had formed part of a house-heating apparatus. This I set up outside the building and inside of a big sugar hogshead, blocking it up from the bottom about 6 inches, led the exhaust pipe from the

March, 8896. we were using the brake. I will not weary your readers with de-tails, but give a summary of the results condensed from several series of trials with different loads. The brake arm was 5.252 feet long, or the radius of a 33 foot circle, the friction pulley 3o inches diameter and 3 inches face. Beginning with a light load, we increased it as far as the strength of the friction pulley would allow, and as the last results were practically uniform, stopped when we got Toy,. HP. from the engine. Tabulated they read as follows Lbs. in Scale. a:

In trials I, 2, 3 and 5, the inventor throttled off part of the steam, until I protested, and trials 4, 6, 7 and 8 were made with a full head of steam, showing much better results. The steam was taken from the boilers of a large factory, across a narrow alley-way, and was quite irregular in pressure, but the pipe was thoroughly wrapped with old bagging the whole way to the engine, and the weather was quite mild and thawing during the trials. In order to render my results more intelligible to the parties who employed me, I made a comparison of them, with the quantities of water or steam, shown by various tests as used by other engines, adding another column to show the fuel required per HP. , at an average estimate of 9 pounds of water evaporated from 6o degrees Fah. by r pound of coal, as follows:

Water per H. P. Coal per H. P. Lbs. Lbs. Rotary engine, average of tests Nos. 4, 6, 7 and 8 77. 8.54 Old slide valve single engine 45. 5. Prof, Goss' test of Laval steam turbine 43. 4.78 Prof. Carpitnter's Sibley College test, Corliss single 24. 2.67 compound 16.5 1.83 My own test, at Trenton, Allis triple compound 13.41 2.42 I reduce all these I HP. at ro per cent. less than for brake HP. It is but fair to say that we had to lift all the exhaust 5 feet to get it into the condenser, and I endeavored to console the disappointed inventor by telling him that if he made his exhaust dis-charge downward, to relieve the excessive back pressure, jacketed his cylinder, made his feed-port open quicker, and moved his gates both in and out by a proper cam, thus avoiding the resistance of the heavy spiral springs, which drew them in, he might probably save 25 per cent. ; and as his engine was very compact, worked very smoothly and required no foundation, lie might make it useful on a portable boiler, for saw-mills, 01- I lireshing

FIG. 14.OBSERVATIONS IN AN OLD SHOP.-SEE PAGE 198. engine into it near the top, and carried a pipe from the bottom back in the building into a tank placed on a platform scale, so that the condensed water could be all caught and weighed. To condense it, we brought a hose from a convenient hydrant, and poured a stream of water into the top of the boiler, which had a 3 inch flange all around it, and this water, flowing down through the fire tubes, came up around the outside and overflowed through a gap cut in the rim of the hogshead. This answered my purpose perfectly, and gave me a steady flow of condensed water into the tank, which was weighed every five minutes, while

Water per H. P. Coal per H. P. Lbs. Lbs. Rotary engine, average of tests Nos. 4, 6, 7 and 8 77. 8.54 Old slide valve single engine 45. 5Prof, Goss' test of Laval steam turbine 43. 4.78 Prof. Carp mter's Sibley College test, Corliss single 24. 2.67 L 4 compound 16.5 1.83 My own test, at Trenton, Allis triple compound 13.41 1.42 I reduce all these r HP. at io per cent. less than for brake HP. It is but fair to say that we had to lift all the exhaust 5 feet to get it into the condenser, and I endeavored to console the disap-pointed inventor by telling him that if he made his exhaust dis-charge downward, to relieve the excessive back pressure, jacketed his cylinder, made his feed-port open quicker, and moved his gates both in and out by a proper cam, thus avoiding the resist-ance of the heavy spiral springs, which drew them in, he might probably save 25 per cent. ; and as his engine was very compact, worked very smoothly and required no foundation, he might make it useful on a portable boiler, for saw-mills, or threshing machines, where the sawdust and straw supplied fuel without expense, but that I could not in conscience recommend it where fuel had to be purchased for it. I felt sorry for him, for he was an ingenious fellow, who, hav-ing got up a good friction coupling, which he sold for a fair price and which the purchasers re-sold for ten times what they paid him, thought it advisable to turn his profits and his wits to the im-provement of the steam engine, with the result as shown.

* * *
THE FITCHBURG MACINE WORKS, Fitchburg, Mass., are very busy on heavy drill presses and lathes, being obliged to run several nights a week to keep up with orders. When this is found necessary the men are given a fifteen minute lunch, prepared by a caterer, with their pay going on just the same. Recently Mr. Chapman, the genial manager, extended the lunch time another fifteen minutes and passed around cigars and pipes to while away the extra time. They have built a very complete pattern-makers' lathe for the Herreshoffs, at Bristol, R. I., which is the most convenient and rigid lathe of the kind we have seen. It has a gap, made by running the top of bed back, and has a complete lathe carriage which is mounted on substantial ways th3 same as an engine lathe. For large turning, the back end of lathe spindle is threaded for face-plate, as is usual, and is provided with a cap to protect the thread of spindle when face-plate is not in use.
Machine Company LATHES PLANERS--SHAPERS RADIALS

Sixth pic down
AMERICAN MACHINIST Vol. 56, No. 2 March 1896
HELICAL GEARING.
/ 7 pic down
MACHINERY. March, 1896.
March, 1896. MACHINERY. HELICAL GEARING. CISNARF. Very little information can be found in text books on this sub-ject ; it is lightly treated, a few crude cuts given ; the rest being left for experience to teach. It appears that writers are unable to get hold of anything but theoretical information on the sub-ject; why, it is hard to explain, for this style of gearing and its modifications are in universal use, but generally in connection with a " rolling" process. From the first, straight-faced spur gears have given endless trouble when used on delicate work (when I say " delicate," I do not mean always fine, light work, but that which needs careful working to produce good results), the uneven rotation produced, especially when the teeth were a little worn, marked the strips of product periodically. When small gears were used, such as " roll pinions," the small number of teeth made a very short arc of con-tact between the teeth, and the power transmitted at great angles; the resultant motion was uneven and unsatisfactory. A partial remedy for this was the scheme of " multiple-faced " gears; one of these is shown in Fig. t ; it is an equivalent of sev-eral narrow-faced gears, joined together in such a position that the teeth of one section are slightly ahead of the one adjacent. The result obtained is, that at all times a pair of teeth is at or near the point of maximum efficiency, the line of common cen-ters. When a tooth is at the point A, and about to end its con-tact with its partner on the other gear, a pair at C is in its best position, accomplishing the desired result, a continuous motion. A few objections are raised against this system: the teeth lack continuity in regard to face, and unless the " shroudings " are used between the different faces, the moulding is bad, especially if the num-ber of faces be small. Where the " shroudings " are used, the effective face is greatly diminished, leaving a very nar-row tooth liable to get the whole stress. It is not an easy matter to get the teeth on two patterns exactly alike, in this " advancement " of face, which is neces-sary, if the gears are to run satisfactorily. It is not easy for the moulder, when there are several faces, to avoid distort-;Ã¢â‚¬â€ .,7,0-1 a little iq Pnotio'h 201 giving, at all times, a pair of teeth at the line of common centers. The gears work well, are not very difficult to make, except in moulding, for the pattern is twisted in drawing out of the sand, and a careless workman is liable to injure the mould. In laying out such a gear on paper, the shape, pitch and sizes of teeth are determined exactly as with a straight-faced gear, the end and side clearances being in no way affected by the helix ; the end view, as in the figure, being available for a straight face also. It is commercially impossible (reckoning cost as a possi-bility) to work the teeth on the pattern by hand ; it is pretty cer-tain that they cannot in any case be cut by hand. The cutter to be used on a machine should be laid out in the drawing-room, and not left for the shopmen to do. The pattern is generally in two pieces (not counting the end flanges), and is divided at the center line, each half of it being worked separately; the cutter is used as shown at R, revolving perpendicularly to the center line of the shaft, the gear being revolved the amount of helical pitch. In many cases of hurried work, also in thoughtless work, the shape and size of the cutter has been made to correspond with outlines as shown on the end view, simply that the space to be cut is the space shown there ; a glance at the figure will show that the dis-tances in the direction of the line F, perpendicular to the helices, are the determining measurements for the cutter. The exact out-line of this is obtained as in Fig. 4, two teeth are drawn showing the end view of the space to be cut, as denoted in Fig. 3 ; the line 0 H above shows the pitch of the helix for half the face 0 L. Numerous short lines are drawn along the tooth outline, the intersections being projected to the line 0 L. Taking 0 as a center, small arcs are drawn from these projected intersections on 0 L to the " helix 0 H: the intersections of the circular arcs are Fig. 3

used between the different faces, the moulding is bad, especially if the num-ber of faces be small. Where the " shroudings " are used, the effective face is greatly diminished, leaving a very nar-row tooth liable to get the whole stress. It is not an easy matter to get the teeth on two patterns exactly alike, in this " advancement " of face, which is neces-sary, if the gears are to run satisfactorily. It is not easy for the moulder, when there are several faces, to avoid distort-ing the mould ; even a little is enough to ruin the casting. The teeth cannot be cut in the casting of such a gear, except by cutting the sections separ-ately, then bolting them together, a job that our best shops would shun, from a commercial point of view. anyway. A natural development of the staggered teeth was some method of providing for continuous faces and still preserve the advantages of the advanced faces ; this was found by making simply a " slanting" face. A straight line D, as in Fig. 2, laid on a flat sheet, then wrapped around a cylinder, gives the ' spiral " or helical face ; if a helix is a spiral, it is proper to call it thus, but I understand that a spiral is a plane figure. Such a slant as given to this line, if applied to a gear face, would give an immense end thrust when running; so, to avoid this, these helices are always used in pairs, slanting in opposite directions (Fig 3). Assuming the pitch, number and shape of teeth to be settled, also the face, we have enough data to determine the slant of the helix. The first point to consider is the nature of the work to be done. If comparatively light, and continuous running is the object in view, the helical pitch may be made equal to the tooth pitch, maybe more if the face is large ; but if the work is heavy, good results have been obtained by making it about three quarters of the pitch, but in no case should the angle (Fig. 2) exceed thirty degrees. From this it is apparent that the face chosen for the gear has considerable influence on the helical pitch. Too large an angle produces " wedging," when running, and could be in-creased to such a point that the teeth would jam and gears refuse to rotate. The working of a pair of these gears can be examined in Fig. 3 ; as the tooth shown on the line of centers is supposed to be a sec-tion at the center line of the face, it can be easily seen that as it rolls toward the point of breaking contact, the outer portions of the next tooth are taking the position that this one has just left, Fig. 4 Fig. 1 Fig. 2 projected back to the lines cutting the tooth curve, care being taken to intersect with the same line from which the first projec-tion was made. The points, when joined by a carefully drawn line, will give the shape of the curve, referred to the direction F, which is the outline of the cutter. There are other methods of determining this shape, but the one given is as short as any, and is recommended for its simplicity, and also for its possible use in many other cases requiring a similar process. Soft wood teeth, on a pattern cut this way, are not satisfactory ; the wood tears, splits and produces a ragged surface, which, when smoothed' down by hand, destroys the shape of the tooth ; using a soft wood center with roughed-out hardwood teeth fas-tened to the pattern in any of the good modern methods, the ma-chine cutting will be done easily, quickly and result in a good job. The machine moulding of helical teeth is a very difficult task, and is practiced only where gears of large diameter are required, which is not very often. In England there is a tendency to use these faces on very large gears, but in this country we have few, if any, of such ponderous combinations. These remarks deal with gears running on parallel shafts only, no reference being made to the fancy combinations sometimes used as spur gears on perpendicular shafts. A combination of spur and helical faces appears in a patented gear, and its merits and demerits (it has both) cannot be discussed here. The outline is, roughly, a straight gear in the middle, with helical face, pitching in oppo-site directions on each side (Fig, 5).
HELICAL GEARING -- LATHES PLANERS--SHAPERS RADIALS

11 th pic down
AMERICAN MACHINIST-Section Vol. 56, No. 2 March 1896
Page 203 Mechanical-drawing-Circular-development-intersection-layout double Helical gears

Machinery-Magazine-March-1896-vol-2-no-7-page-203-bot-Mechanical-drawing-Circular-development-intersection-layout / pic down
MACHINERY. March, 1896.
March. 1896. PRACTICAL TALKS ON MECHANICAL DRA\A'- ING. (4). Louis RompoN. SHEET XII. DEVELOPMENT OF A RIGHT ELBOW. Draw the top and front views of a right elbow, to the dimen-sions given in Fig. 17. The development of the lower part of the elbow is obtained as shown in Sheet X. The development of the L part is obtained in the same manner, and, for the sake of the DEVELOPMENT RIGHT EL E300/ FIG. 7. symmetrical appearance of the sheet, is represented in the draw-ing above the first pattern. A good general rule to observe in making the cut is to make it on that part of the pattern that will require the least seam. The reason for this is obvious. SHEET XIII. DEVELOPMENT OF A FIVE-PIECE ELLOW. In Fig. IS is shown the front and top views of a five-piece elbow, together with its development. The top view is not neces-sary in order to obtain .the development, and is given only as an additional exercise in drawing. If, however, the top view were not given it would be necessary to draw a semi-circle on the base line as diameter, in order that the required division points might be obtained. First draw the front view of a 2-inch cylinder of indefinite height. At IX inches above the base draw a line parallel to the base and extend it to the right. The distance that this line is extended depends upon the sharpness with which it is required that the bend should be made; the shorter the extension the sharper the bend. In this instance the line is extended to the right a distance equal to the radius of the cylinder, making a line 3 inches in length. Take this distance in the compasses and DEVELOPMENT FIVE-PIECE ELBOW 1 203 these angles are the joints of the elbow. The lowest one of these joints crossing the indefinite height of the ey inder as first drawn completes the lowest part of the elbow. To obtain the second part, draw lines from the extremeties of the top of the first joint at right angles to the center line of the second part until cut by the sec-md joint. Ã¢â‚¬Â¢ The remaining parts are obtained by the same method. The development of the lowest part is obtained as in the previ-ous sheet. The three cent( r Rifts are identical ; therefore it will only be necessary to make one pattern.. Draw a horizontal line to represent the center line of the front view. From the pattern of the lowest part already obtained, extend the vertical end lines upwards and on these lines cut off, on either side of the center line, the throat measurement as shown in the front view. The greatest width of each part is obviously at the back, andis. shown in the center of the pattern. All intermediate distances between these two extremes are found from the front view, In Sheet X. all the elements of the front view and development are drawn in full. In Fig. IS these lines are not all shown, but should be drawn in pencil by the student. They are shown, however, on the next to the lowest part of the elbow. The coi responoing ele-ments should be drawn on the lay-out of the pattern and the (Its-tances taken above and below the center lines, as obtained from the front view. SHEET XIV. DEVELOPMENT OF THREE INTERSECTING PIPES. Draw a cylinder 4 inches high and 2 inches in diameter. At the middle of one side intersect it with a cylinder of I IZ inches diameter, and cut off yt inch. On the opposite side intersect at 6o degrees with a cylinder of I IZ inches diameter Let the lower edge of the inclined cylinder intersect the larger cylinder at Iz DEVELOP/WEN" T oP- THREE INTERSECTING PIPES nALF PATTE,NS FIG. 19. inch from its ba,.e. Draw front and top views and half-patterns of each pipe. First draw the front and top views of the three pipes to the

FIG. 7. symmetrical appearance of the sheet, is represented in the draw-ing above the first pattern. A good general rule to observe in making the cut is to make it on that part of the pattern that will require the least seam. The reason for this is obvious. SHEET XIII. DEVELOPMENT OF A FIVE-PIECE ELEOW. In Fig. 18 is shown the front and top views of a five-piece elbow, together with its development. The top view is not neces-sary in order to obtain . the development, and is given only as an additional exercise in drawing. If, however, the top view were not given it would be necessary to draw a semi-circle on the base line as diameter, in order that the required division points might be obtained. First draw the front view of a 2-inch cylinder of indefinite height. At inches above the base draw a line parallel to the base and extend it to the right. The distance that this line is extended depends upon the sharpness with which it is required that the bend should be made ; the shorter the extension the sharper the bend. In this instance the line is extended to the right a distance equal to the radius of the cylinder, making a line 3 inches in length. Take this distance in the compasses and DEVELOPMENT., F7VE-FYECE ELBOW FIG. 18. with the right-hand end of the line as a center describe a quad-rant in the direction of the bend of the elbow. Also at the point taken as a center, erect a perpendicular to meet the end of the quadrant. Divide the right angle thus formed into four equal angles ; that is, one less than the number of parts composing the elbow. This may be done by first dividing the angle into two equal angles by aid of the 45 degree triangle, and then by trial with the dividers finding upon the arc already drawn the center points of these angles. The sides of the angles serve as center lines of the various parts of the elbow. The bisectors of each of DEVELOPMENT OF THREE INTERSECTING PIPES. Draw a cylinder 4 inches high and 2 inches in diameter. At the middle of one side 'intersect it with a cylinder of r IZ inches diameter, and cut off 4 inch. On the opposite side intersect at 6o degrees with a cylinder of I IZ inches diameter Let the lower edge of the inclined cylinder intersect the larger cylinder at IZ DEVELOPA4ENTo,-THPF:E /NTERSE.0 TING PIPES FIG. 19. inch from its base. Draw front and top views and half-patterns of each pipe. First draw the front and top views of the three pipes to the dimensions given, disregarding their intersections. The method of finding the curve on the front view made by the intersection of the two pipes at right angles will first be considered. Divide the small cylinder into a number of equal parts, by describing a semi-circle on its base and on the semi-circle stepping-off the required divisions. This semi-circle answers the purpose of an end view. As the axes of the two cylinders intersect at right angles, each quarter of the curve is like each of the other quar-ters, and it will therefore only be necessary to show how a guar ter of the curve is obtained. The points of division taken are shown in the two views at A, B, C and D. These letters repre-sent similar lines in each view. Through these points draw ele-ments of the small cylinder parallel to its axis. From where these elements intersect the top view of the large cylinder project lines down to the front view, and where these projecting lines intertsect the corresponding elements in the front view will be points on the required curve. This method is shown in the drawing in the case of the point C. The point C is one of the equal divisions of the semi-circle representing a partial end view of the small cylinder. Through it the line C E is drawn as an ele-ment of the small cylinder parallel to its axis. This element in-tersects the top view of the large cylinder at point E. From this point the vertical projecting line E E is drawn, and where it intersects the line C E of the front view is a point on the curve. In this manner find a number of points and join them by a smooth curve.
LATHES PLANERS--SHAPERS RADIALS

Page 204, 12th pic down
AMERICAN MACHINIST-Section Vol. 56, No. 2 March 1896
More Descriptive Geometry, sheet metal layout.
/ pic down
MACHINERY. March, 1896. page 204
204 MACHINERY. March, 1896. The curve formed by the intersection of the large cylinder and the smaller one inclined to it is found in a similar manner. As the axes do not intersect at right angles, only the halves of the curves are similar, and it will therefore be necessary to find one half of the curve. In the top view use the elements already found, extending them to' the right. At some point on the axis of the inclined cylinder describe a semi-circle of I IZ inches diameter, the diameter to be drawn at right angles to the axis. Divide this semi-circle into the same number of parts that the semi-circle in the top view is divided into. The points on the curve formed by the intersection of the two cylinders are found in the manner already described. One such point is shown at F, together with the method for obtaining it. The top view of the inclined cylinder shows an ellipse. Points on the ellipse may be found by the intersection of any element of the top view with the projection of a similar element of the front view. Such an intersection is shown at the point F on the ellipse. This ellipse plays no part in obtaining the pattern, and therefore would not be required to be drawn, if the laying out of the pat-tern is the only thing desired. Having finished the two views, together with the intersections, it is now required to lay out the patterns. It is obvious that each pattern may be cut into two similar halves. It will therefore be necessary to lay out only one-half of each pattern. Begin with the laying out of the half-pattern of the large cylin-der. Extend the top and bottom lines in the front view indefin-itely to the right and cut off by vertical lines an area equal to one-half the surface of the cylinder. The method for doing this was given in Sheet X. In the top view of the large cylinder observe what portion of the circle is embraced by the intersecting cylin-ders and divide this portion of the circle into a number of equal parts. Take one of the parts in the dividers and step off an equal number on the pattern, and through the points draw vertical lines. From the points of division on the circle drop vertical lines across the front view of the cylinder. The vertical lines on the cylinderÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Âor elements, as they are customarily calledÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Âcol-re-spond line for line with the vertical lines on the pattern. It is only necessary then to project horizontal lines from the intersec-tion of the elements with the curve previously found over to the corresponding elements on the pattern. A series of points will thus be found which when joined by a smooth curve will give the desired cut in the pattern. The principle is similar to that given in the previous sheet. The half-pattern for the inclined pipe is readily found by taking any line, as G, for a base line, and laying off the distances above and below this line on the various elements. By observing the part of the inclined cylinder above the line G, it will be seen that it is simply a cylinder with a slant cut. We have already had a similar problem in Sheet X. The part below the line G is ob-tained in a like manner. The same process is applied in obtain-ing the half-pattern of the small projecting pipe at the left. SHEET XV. DEVELOPMENT OF TAPERING SECTION OF PIPE. ,

lines. In the top view connect the alternate extremeties of the elements by the lines b A, c B, dC, e D,f E, and g F. Draw the projections of these lines in the front view. These are desig-nated by lines lettered similarly to those of the top view. These last lines form a series of " auxiliary " elements, the purpose of which will appear when laying out the development. It will be seen that of all the elements drawn in the front view, a A and g G alone show true lengths. The next step then is to find the true lengths of the other elements. Let us first find the true length of the line b B in the front view. Draw a right angle having the altitude of the taper for one side, and the line b B in the top view for the other side. The hypotenuse of third side of the right triangle, will be the true length of the line b B. Such a triangle is shown in Fig. 20, at the extreme right, as the smallest in the nest of triangles. As the distance be-tween the two pipes is constant, one side of all the triangles will be the same in this case 2 inches. To find the true length of c C in the front view, proceed in the same manner as in find-ing the true length of b B. For the base of the triangle lay off a distance equal to c C in the top view, take the altitude of the taper for the other side of the right angle, and then draw the hypotenuse, which is the true length of the line c C. In like man-ner obtain the true lengths of d D, e E, and f F. It is next necessary to find the true lengths of the auxiliary ele-ments b A, c B, dC, e D, f E, and g F. These are shown by the nest of triangles in the center of Fig. 20. The letters at the top of the triangles are given in the order in which the lines are drawn. To find the true length of b A, draw a right angle having for one side the altitude of the taper and for the other the line b A
DEVELOPMENT OF TAPE RING INTERSECTION OF TWO ROUND PIPES PIPEs

2:2' FIG. 20. in the top view. The hypotenuse of the right-angled triangle is the true length of b A. In a like manner find the true lengths of c B, de, e D,f E, and g F. We now have all the data required for laying out the pattern. Draw a line equal to g G of the front view. Such a line is shown

[.4 2H L FIG. 7.
symmetrical appearance of the sheet, is represented in the draw-ing above the first pattern. A good general rule to observe in making the cut is to make it on that part of the pattern that will require the least seam. The reason for this is obvious. SHEET XIII. DEVELOPMENT OF A FIVE-PIECE ELLOW. In Fig. 18 is shown the front and top views of a five-piece elbow, together with its development. The top view is not neces-sary in order to obtain . the development, and is given only as an additional exercise in drawing. If, however, the top view were not given it would be necessary to draw a semi-circle on the base line as diameter, in order that the required division points might be obtained. First draw the front view of a 2-inch cylinder of indefinite height. At inches above the base draw a line parallel to the base and extend it to the right. The distance that this line is extended depends upon the sharpness with which it is required that the bend should be made ; the shorter the extension the sharper the bend. In this instance the line is extended to the right a distance equal to the radius of the cylinder, making a line 3 inches in length. Take this distance in the compasses and DEVELOPMENT., F7VE-FYECE ELBOW

FIG. 18. with the right-hand end of the line as a center describe a quad-rant in the direction of the bend of the elbow. Also at the point taken as a center, erect a perpendicular to meet the end of the quadrant. Divide the right angle thus formed into four equal angles ; that is, one less than the number of parts composing the elbow. This may be done by first dividing the angle into two equal angles by aid of the 45 degree triangle, and then by trial with the dividers finding upon the arc already drawn the center points of these angles. The sides of the angles serve as center lines of the various parts of the elbow. The bisectors of each of
DEVELOPMENT OF 'rlIREE INTERSECTING PIPES. Draw a cylinder 4 inches high and 2 inches in diameter. At the middle of one side 'intersect it with a cylinder of r IZ inches diameter, and cut off 4 inch. On the opposite side intersect at 6o degrees with a cylinder of I IZ inches diameter Let the lower edge of the inclined cylinder intersect the larger cylinder at IZ

FIG. 19. inch from its base. Draw front and top views and half-patterns of each pipe. First draw the front and top views of the three pipes to the dimensions given, disregarding their intersections. The method of finding the curve on the front view made by the intersection of the two pipes at right angles will first be considered. Divide the small cylinder into a number of equal parts, by describing a semi-circle on its base and on the semi-circle stepping-off the required divisions. This semi-circle answers the purpose of an end view. As the axes of the two cylinders intersect at right angles, each quarter of the curve is like each of the other quar-ters, and it will therefore only be necessary to show how a guar ter of the curve is obtained. The points of division taken are shown in the two views at A, B, C and D. These letters repre-sent similar lines in each view. Through these points draw ele-ments of the small cylinder parallel to its axis. From where these elements intersect the top view of the large cylinder project lines down to the front view, and where these projecting lines intertsect the corresponding elements in the front view will be points on the required curve. This method is shown in the drawing in the case of the point C. The point C is one of the equal divisions of the semi-circle representing a partial end view of the small cylinder. Through it the line C E is drawn as an ele-ment of the small cylinder parallel to its axis. This element in-tersects the top view of the large cylinder at point E. From this point the vertical projecting line E E is drawn, and where it intersects the line C E of the front view is a point on the curve. In this manner find a number of points and join them by a smooth curve.

12 th pic down page 208
AMERICAN MACHINIST-Section Vol. 56, No. 2 March 1896
Page 208 Pittler Lathe- Mechanical design 1896, yes, there was some even then, yea, Machine MATH.
/ 13 pic down
MACHINERY. March, 1896. page 208
MACHINERY. Design Math.
21 blow off, assuming that C 25 inches, the other data being the same as before ? (b) With a steam pressure of 87 pounds and C-25 inches, what should be the weight of W ? 2. If, in addition to the weight W an additional weight of 5 pounds were suspended at P in Fig. 21, what pressure could be carried ? Use the data given in Examples i and 2 of the text. 3. If a wheel and axle mechanism has a drum 20 inches in diameter and a wheel 612 feet in diameter, how great a load can be raised by exerting a pull of 125 pounds, neglecting frictional losses ? 4. In Fig. 24, let the diameters of the wheels be as follows : Of C 35 inches, D, 6 inches, E, 18 inches and F, 20 inches. If a pull of moo pounds be exerted on C, how great a resistance could be overcome by F ? F" ANSWERS TO EXERCISE 4. T. (a) i6o foot-pounds. (b) 'ckÃƒâ€šÃ‚Â° \\ Fig. 25 illustrates the problem. The moment = F x 0 A and 0 A= 4/42x42 = 5.66, nearly. Hence, moment= 2ox 5.66 = 113.2 foot-pounds. 2. No ; it will turn in a right-handed direction. 3. This is solved like the examples in the text, and the reac-tions, of course, will remain the same.. 4. The problem is to be solved as before, except that the moment of the force should be obtained by the method used in Example i (b). 8' FIC.25 * * * tions, of course, Nvill remain the same. 4. The problem is to be solved as before, except that the moment of the force should be obtained by the method used in Example r (b). * * * THE " PITTLER " LATHE. On account of peculiar characteristics, we think the lathes designed by W. von Pittler, of Leipzig-Gohlis, will prove of interest to many of our readers, for although these are not exactly engineers'. lathes, yet they embody so many ingenious details of mechanism that they are well worthy of attention, and in many shops they might fill a useful place. In the first place a glance at the general design (Fig. I) shows that these lathes differ in almost every point of detail from any of the standard kinds with which we are familiar, and nearly everything seems to run coun-ter to our preconceived notions of what a lathe should be yet, when considered more closely, they are seen to be admirably adapted to the lighter class of work which they are designed to accomplish. In fact, they are more than mere lathes, they are universal machines.
The bed seen in section in Fig. 2, B, reminds us of the now antiquated triangular-bar bed, which was too weak to resist tor-sional stress, the principal stress which a lathe bed has to endure. But by adopting a triangle of large section, and taking off the top edge, strength and stiffness are secured, while the recessing of the under side provides a place for the leading screw, which is thus protected absolutely from the abrading action of grit and dust. These are screw-cutting lathes, but there is no long train of spur change wheels, or swing plate for studs. The screw-cutting is done through a worm located on the tail of the headstock man-drel in the small lathes, as in Fig. 3, or on a second spindle, as in Fig. r, driving a worm wheel on a swing shaft, the motion being transmitted through bevel wheels to the leading screw. Changes in rate of thread are effected by the substitution of worm wheels having different numbers of teeth, and by different worms. In the larger lathes there are two worms, one being just twice the diameter of the other, either being used as required. The bearing position and worm on the mandrel, and worms on the change spindle, together with a dividing plate, spirals of numerous pitches can be cut. The construction of the slide rest is peculiar. It is not fixed rigidly to the bed, but swivels around it. The saddle C, Fig. 2, which fits the bed and slides longitudinally on it, is circular on the outside A split ring encircles this, and can be clamped in any position. There is a lug H on the split ring with a drilled hole, and in this hole fits and swivels the socket of the top or travers-ing slide. The leading and most original feature of the lathe lies in this slide rest. It is a universal rest, the universality of its movements being effected in a most simple manner, namely, by the pivoting of the tool in two directions, at right angles with each other, one movement being that of rotation in an axis at right angles with the bed, the other that of rotation in an axis at right angles with the first. There are also, of course, the longi-tudinal movements of the rest by leading screw, and the feed movement of the tool slide inwards and outwards by hand with the handle T and screw. The movement round the lathe bed serves as a means of ad-justment for the height of the tool point, so that no packing up is necessary. Also, while in ordinary turning the tool slide is hori-zontal, or approximates to that position, in wheel cutting the tool slide is brought into the perpendicular position for convenience of feeding the blank upwards and downwards in front of the milling tool, which revolves in the lathe axis. Or an angular position can be given to the blank for cutting bevel wheels. By setting the rest at an angle taper turning is readily done. Convex and con-cave surfaces can be turned truly by swivelling the tool slide around its pivot or post in the socket H. In some of the larger en-gineers' lathes the circular turning is made automatic. This is illus-trated in the first figure. A worm wheel is attached to the bot-tom end of the pivot, and is driven by a worm actuated by means of a shaft with Hooke's joints, coming from the headstock gear. Milling can be readily performed in consequence of the univer-sality of movement of the rest. Spur and bevel, worm and helical wheels, milling cutters, tap and reamer grooves can all be readily shaped in these lathes. The cutting or milling tools always run between centers, and the work is carried in the rest, so that there is no need of an overhead movement. The smallest lathes made are of 3 inch centers, the largest of 12 inch. Lathes from 6 inch to 12 inch centers are made of heavy pattern, and with back gear for the use of engineers especially, in first figure. The lighter lathes are suitable for mechanicians of various classes, being particularly serviceable to those who want a universal tool capable of fulfilling well the functions of the turning and screw-cutting lathe, the milling and wheel-cutting machines.
March, 1896.
ing for the bevel wheels is pivoted on the axis of the leading screw, so that it is readily accommodated to whatever worm wheel hap-pens to be in gear. The leading screw is driven forward or back-ward by one or the other bevels, Kr, Kr, Fig. 3, either of which is thrown into or out of gear as required with the bevel wheel on the end of the leading screw. The equipment for screw cutting comprises seventeen worm wheels and two worms, one being one-threaded, and one five-threaded. The numbers of teeth on the worm wheels range between twenty and eighty, and the numbers of threads per inch that can be cut by various combinations range between ten and four hundred. By changing the relative positions of the worms and worm wheels, placing the worm wheels on the mandrel, and worms on the change spindle, together with a dividing plate, spirals of numerous pitches can be cut. The construction of the slide rest is peculiar. It is not fixed rigidly to the bed, but swivels around it. The saddle C, Fig. 2, which fits the bed and slides longitudinally on it, is circular on the outside A split ring encircles this, and can be clamped in any position. There is a lug H on the split ring with a drilled hole, and in this hole fits and swivels the socket of the top or travers-ing slide. The leading and most original feature of the lathe lies in this slide rest. It is a universal rest, the universality of its movements being effected in a most simple manner, namely, by the pivoting of the tool in two directions, at right angles with each other, one movement being that of rotation in an axis at right angles with the bed, the other that of rotation in an axis at right angles with the first. There are also, of course, the longi-tudinal movements of the rest by leading screw, and the feed movement of the tool slide inwards and outwards by hand with the handle T and screw. The movement round the lathe bed serves as a means of ad-justment for the heizht of the tool mint. so that no nackinz 11.13 is ÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Â The Practical Engineer, London.

THE Scientific Machinist has improved its appearance and value with the new year, having added H. F. Cook and W. H. Wakeman to its editorial staff,, and other well-known, writers to its list of contributors.

14th pic down page 208
AMERICAN MACHINIST-Section Vol. 56, No. 2 March 1896
Page 210 Billings-and-Spencer-Co-drop-forging-die-vault
/ 13 pic down, Blueprints-drawings-Drafting, Billings and Spencer
MACHINERY. March, 1896. page 210

page 210 MACIIINERY. March, 1896. Blueprints. (The only thing but expensive photography before the Xerox age)
whith better than the bare lines indicate. It also takes time and paper, and the Ã¢â‚¬Å¾drawing." finished as before and photographed. costs money, and the same time spent in other ways would pro- The first negative was a permanent record of the original, and each duce more tangible results. ! 'I-subsequent negative showed the changes from the original. In The size sheet that a drawing shall be made on is fixed this way the records were kept full and exact and at little cost. largely by the work to be done and the kind of work. When a In fact this way would prove a saving in many offices and at the firm receives drawings from many other com-panies, to fill in the details of their apparatus, it is impossible to maintain standard sizes of sheets. Where all the work is original in a shop, then standard size sheets should be rig-idly adhered to. As the kinds of drawing papers and tracing cloth used come in rolls, the general inclination seems to be towards a 24 X 36-inch full sheet. 18x 24-inch small sheet, 9 X 12-inch for sketches, tables, etc. , and 36X 48-inch double size. This enables one to cut standard sheets without waste. The 36-inch tracing cloth, being usually 37 to 38 inches wide, leaves ample space for trimming. The kind or quality of paper is also decided by the governing conditions. Some shops make the drawings in pencil on a cheap grade of paper, and as soon as completed the draw-ing is traced on cloth in ink and " blue printed" for shop use, and the original is de-stroyed. The tracing is kept in the drafting-room for permanent record. Some use a thin linen or bond paper, and ink in the drawing over the pencil lines ; blue prints being made in the usual way and the original is preserved. Certain lines of work are handled to good ad-vantage, using cross-section paper and inking in the drawing over the pencil lines and blue printing the necessary copies. While I am much in favor of this method of handling the work, it is not applicable to all kinds of draw-ings, and when not readily applicable it proves very disadvantageous. One way I have made use of has proved very satisfactory for work where the design is changed quite often in little details, the main construction remaining the same. The drawings were made on I2XIS inch sheets, one or two details on a sheet, in large scale. I used a buff paper of good quality and inked the drawing in on the paper. The inked drawings were PRESIDENT'S OFFICE.-BILLINGS & SPENCER CO.

same time maintain true records. The received by the men in the shop in every case, and I never heard any man express a preference for the large scaled drawing. With this method it was impossible to scale the drawings, and the shopmen were obliged to come to the drafting-room for informa-tion, and could have no excuse for going wrong. prints were favorably stroyed. The tracing is kept in the drafting-room for permanent record. Some use a thin linen or bond paper, and ink in the drawing over the pencil lines ; blue prints being made in the usual way and the original is preserved. Certain lines of work are handled to good ad-vantage, using cross-section paper and inking in the drawing over the pencil lines and blue printing the necessary copies. While I am much in favor of this method of handling the work, it is not applicable to all kinds of draw-ings, and when not readily applicable it proves very disadvantageous. One way I have made use of has proved very satisfactory for work where the design is changed quite often in little details, the main construction remaining the same. The drawings were made on 12 X 18 inch sheets, one or two details on a sheet, in large scale. I used a buff paper of good quality and inked the drawing in on the paper. The inked drawings were

* * *
March, 1896.
THE BILLINGS & SPENCER CO. The accompanying photographs, taken very recently, give an idea of the extent of the business built up by Mr. Charles E. PRESIDENT'S OFFICE.-BILLINGS & SPENCER CO. same time maintain true records. The prints were favorably received by the men in the shop in every case, and I never heard any man express a preference for the large scaled drawing. With this method it was impossible to scale the drawings, and the shopm en were obliged to come to the drafting-room for informa-tion, and could have no excuse for going wrong. SECTION OF DIE VAULT-BILLINGS & SPENCER CO. photographed on 8 X 10 plates and blue prints made from negatives, mounted on cards and shellaced in the regular way. The result was a small card drawing as clear and distinct as an engraving, readily handled for machine work or bench work. Changes could be made on the original drawing by erasing or pasting patches of new these * * * THE BILLINGS & SPENCER CO. The accompanying photographs, taken very recently, give an idea of the extent of the business built up by Mr. Charles E. Billings, president of the company, who is seen at his desk in the first view. His article, which appeared in our issue of May, 18g5, gives an account of the growth of the drop forging industry, which has been largely developed by his energy and skill. The die vault, of which only a section is shown, consists of several rooms in a build-ing as nearly fire-proof as possible, and con-tains tons of tool steel, whose value mounts up into the hundred thousands of dollars. The hammer shop is well filled with drop hammers from various makers, the later ones being of their own manufacture and being exceedingly heavy in design. To one who has never witnessed the drop-forging process it is quite a revelation to walk down the long row of hammers and watch the heated metal bars assume shapes that are both intricate and interesting, and it seems almost wonderful that metal can be induced to flow into all the corners and crevices of the dies. Copper commutator bars are also forged here, and this depart-ment always presents a busy scene. The machine room is largely supplied with milling machines, mostly of the Lincoln type, while drills and " edgers " (which are really vertical mills, generally with numerous spindles) abound.

THE Scientific Machinist has improved its appearance and value with the new year, having added H. F. Cook and W. H. Wakeman to its editorial staff,, and other well-known, writers to its list of contributors.

14 th pic down page 211
AMERICAN MACHINIST-Section Vol. 56, No. 2 March 1896
Page 210 33333333
/ 15 pic down
MACHINERY. March, 1896. page 212
man many pointers, in a quiet unassuming way, which the fore-man couldn't get mad at if he wanted to, and he has finally come to rely on him for advice on many subjects, in fact he is what might be called a " shop adviser " in the matter of tools and work, and he has made himself invaluable. The foreman has his hands full with the work of keeping things moving in the shop, and hasn't the time to look after tools and appliances. as this man has. He seems to be a fixture in that shop, anyhow. March, 1896.

SHRINKING AND FORCING FITS. A question which no doubt has puzzled many of your readers, and has been the cause of many inquiries in different mechanical papers, and to which as yet the writer has not seen a very satis-factory answer, is the amount to be allowed for shrinking and forcing fits for different diameters. In your November number I noticed such an inquiry, and the answer, it seems to me, is far from right. The first part of the answer, ' Apply 6 tons per inch of diame-ter," is about correct ; the latter part of the answer, ." Allow ma4 per inch of diameter," is not correct. We will compare this rule with actual practice which the writer re-cently had. The pin that we fitted was 12 inches in diameter, and on being asked by the lathe hand the amount that the pin should be left larger than the hole in the crank, the rule was consulted and we found that 12 X.004 inches gave .048 inch, which would be entirely too much even for a shrink fit. After comparing some previous experiences, we decided to allow .02, the pin was made that much larger and it took a force of ioo tons to press the pin in the crank ; so the writer has decided not to place this rule in his note book. It is the practice in the shop where I am employed, to allow for a 3-inch pin about .008 inch, for a 6-inch pin .012, for a 9-inch pin .o 6, and we have found by experience that these amounts will give pressure of 25, 45 and 65 tons respec-tively, which I consider good practice and has given good results. No hard and fast rule can be given that covers the case ; the nature of the metal and the depth of the hole changes the condi-tions, but the writer believes that if some data from actual practice could be collected and published in your valuable paper, it would prove of great benefit to the average machinist and would do away with a great deal of guesswork which now prevails. * * * J. H. T. It doesn't take long to have the line shaft cleaned up occasion-ally, and it adds much to the appearance of the shop. But don't have a youngster, or man either, fooling around it with a loose -

PORTION OF MACHINE DEPARTMENT-BILLINGS & SPENCER CO.-PAGE 210. It seems to me that every one expects a machinist to give all the information he possesses (it may not be very much, and then again it may) for the asking, and to even look up data and work out problems, just for the fun of it, or for the satisfaction of being consulted ; but even the idea of being a consulting engineer, j5ro fem., doesn't buy smoked herring for breakfast, pay the tailor for creasing your overalls, or even renew your subscription to this paper. When I go to a doctor to see if the big toe that arrested the downward career of a lathe cone is in danger of appendicitis or lockjaw, the doctor looks it over, paints it with something that looks like iron-rust and mud, and says " Good morning." Time, ten minutesÃ¢â‚¬â€I know it means two dollars on my bill at the end of the month. And then I had to consult a lawyer about my right to shoat Mul-gafferty's dog, when he had him chained so his nose came over into my yard, but his three remain-ing feet were planted on his own premises. The dog wasn't even fit for sausage (home-made), but his business end was on my premises and needed attention. Well it took the lawyer just three minutes to tell me to shoot the dog, and then may be fight Mulgafferty after after-wards, etc. This cheerful bit of information cost me five dollars. Now when an aspiring genius comes to me with an alleged new scheme for getting away with the link motion, which, by the way, isn't half so bad as some of its im-provers seem to think, he expects ine to spend a week in showing why it is of no use except for scrap, and would look on me as a high-wayman if I charged even shop time for my services. My advice has probably prevented his invest-ing and losing all his money in the scheme, and yet he would consider a charge of ten dollars as entirely unreasonable. If all men are of the same mind as those who consult me, it will be some time before you'll see a shin-gle reading crank ; so the writer has decided. 110i. to place this rule in his note book. It is the practice in the shop where I am employed, to allow for a 3-inch pin about .008 inch, for a 6-inch pin .012, for a 9-inch pin .o16, and we have found by experience that these amounts will give pressure of 25, 45 and 65 tons respec-tively, which I consider good practice and has given good results. No hard and fast rule can be given that covers the case ; the nature of the metal and the depth of the hole changes the condi-tions, but the writer believes that if some data from actual practice could be collected and published in your valuable paper, it would prove of great benefit to the average machinist and would do away with a great deal of guesswork which now prevails. * * J. I-1, T. It doesn't take long to have the line shaft cleaned up occasion-ally, and it adds much to the appearance of the shop. But don't have a youngster, or man either, fooling around it with a loose

I. PODUNK : Consulting Engineer. :
REPAIR DEPARTMENT-BILLINGS & SPENCER CO.-PAGE 210.
for I wouldn't get enough to pay for the shingle. Wonder how the other fellows make out ?

sleeved blouse or shirt, or in such a manner as to risk his being caught, for this can be made a dangerous job and not half try. A good plan is to have the waste fixed in a little box-like arrange-ment on the end of a long stick, which is filled with waste and moved along the top of the shaft.

14 th pic down page 214
AMERICAN MACHINIST-Section Vol. 56, No. 2 March 1896
Page 214
/ 14 pic down
MACHINERY. March, 1896. page 214

CACULATING THE STRENGTH OF TEETHâ€”DIAMETRAL SYSTEM -- Math Design even in 1896.
214 MACHINERY. March, 1896.

CACULATING THE STRENGTH OF TEETHâ€”DIAMETRAL SYSTEM. JOHN L. KLINDWORTH.
Since writing the article, ' Strength and Proportions of Gear-wheels," it occurred to me that probably some readers of your paper who have to deal with the diametral pitch system, would like the formulae (in the October number) for calculating strength, etc. , of gear-wheels given in terms of diametral pitch. I shall endeavor to do so in the following. When we speak, for instance, of 4 diametral pitch, we mean thereby that for every inch of diameter of the wheel there are four teeth on the circumference, or for every yt inch of the diame-ter one tooth on circumference, and as the circumference is 3.1416 times the diameter, if we multiply X inch X 3.416, we have the corresponding circumferential pitch. Putting this in the form of an equation and denoting circumferential pitch by j, diametral pitch number by N, and 3.1416 by we may write it X it=j5. N N For example take diametral pitch number = 4 to find the cir-cumferential pitch which will equal it, we have: it 3.1416 = ” = = .7854 inch. ir If we now substitute this expression ” for ft in equation (4 b) of the October number we have: it 16.8 X P 7rXbXs â€”= and N= N b Xs 16.8 X P and equation (4 c) becomes zXsXn N = (6a) 16:8 X A the load P which one tooth will sustain is: 7rXbxs 16.8 x N The width of arm at center will be: A / T XbXo.9 W a x thickness 6) N Notations are the same as in the October number. As an example we will take a wheel of 20 inches diameter to transmit 10 HP. at 8o revolutions per minute. Taking A=18,000, we get for width of face of wheel: production, does not give a machinist as varied an experience as is desirable. C. 38. B. R. A., Johnstown, Pa., asks how to calculate change gears for a lathe when it is compounded ? A. This was treated very clearly by W. L. Cheney, in the issue of February, 1895, and has been added to and made as complete as possible in ' Machine Shop Arithmetic," of which he is one of the authors. C.

proceed to the calculations of the volumes of spindles and frus-tums of the same, exactly in the same way as already given for cones. The application of this rule to other forms of bodies will be treated in future articles.

* * * HOW AND WHY.
A COLUMN INTENDED TO CONTAIN CORRECT ANSWERS TO PRACTICAL QUESTIONS OF GENERAL Machine Shop INTEREST. GIVE ALL DETAILS AND YOUR NAME AND ADDRESS, WHICH WILL NOT BE PUBLISHED UNLESS DESIRED.

37. F. W. W. asks: What is the best kind of a shop to learn the trade in ? A. In many ways a repair shop is the best train-ing school one can have, as there is such a variety of work which must be done without special tools, that there is a constant demand for ingenuity on the part of the workman ; but as you have evidently had considerable experience in this kind of work, it might be well to go into another shop which would give you an idea of the finer machine work, and at the same time the ideas gained on repair work would be of benefit to you in almost any shop. The difficulty with a large shop is that it is so thoroughly divided into departments, that each man has one specialty, and does nothing else, which, while it is a great factor in economical production, does not give a machinist as varied an experience as is desirable. C. 38. B. R. A., Johnstown, Pa., asks how to calculate change gears for a lathe when it is compounded ? A. This was treated very clearly by W. L. Cheney, in the issue of February, 1895, and has been added to and made as complete as possible in ' Machine Shop Arithmetic," of which he is one of the authors. C. 39. N. J. A. W. asks the following questions: r. What is the horse power of an engine 5 x 8 inches, plain slide valve, cut-off of stroke, revolutions 240, boiler pressure, roo pounds. 2. The horse power, with cylinder 5 x 8 inches, double ported balanced slide valve, cut-offs stroke, boiler pressure, 125 pounds. 3. The horse power of a tandem compound, cylinders 5 x 8 inches, stroke inches, cut-off stroke. 4. Also give the proportionate water consumption, full capacity. These are interesting questions, but they cannot be answered with much approximation to exactness. To do that a careful examination of the drawings must be made and everything per-tail-1'111g to construction taken into account, as well as general arrangement. It it may be possible to get 2ooâ€¢horse power from one engine, and quite impossible to get roo horse power from another engine with cylinder of equal dimensions. More steam will go through a big hole than through a small one, and so on. If construction is good I should assume that the first named engine could be brought to develop 12 horse power, the second 15, and the third 20, but these figures have no special authority. As to the water consumption, I should assume that it would be crete floor is very satisfactory, and can probably be laid for about $2.25 per square yard. We shall be pleased to hear from any of our readers who have had experience with the wooden floors mentioned. C.

39. N. J. A. W. asks the following questions: 1. What is the horse power of an engine 5 x 8 inches, plain slide valve, cut-off -a- of stroke, revolutions 240, boiler pressure, ioo pounds. 2. The horse power, with cylinder 5 x 8 inches, double ported balanced slide valve, cut-offs stroke, boiler pressure, 125 pounds. 3. The horse power of a tandem compound, cylinders 5 x 8 inches, stroke 48 inches, cut-offs stroke. 4. Also give the proportionate water consumption, full capacity. These are interesting questions, but they cannot be answered with much approximation to exactness. To do that a careful examination of the drawings must be made and everything per-taining to construction taken into account, as well as general arrangement. It it may be possible to get 20oâ€¢horse power from one engine, and quite impossible to get ioo horse power from another engine with cylinder of equal dimensions. More steam will go through a big hole than through a small one, and so on. If construction is good I should assume that the first named engine could be brought to develop 12 horse power, the second 15, and the third 20, but these figures have no special authority. As to the water consumption, I should assume that it would be about 4o pounds per horse power per hour, and that of the three engines the one named in the second instance would use a little the less. It has been assumed that all the engines are non-condensing. 0 H. 40. E. T., Philadelphia, Pa. : We do not know of any book which will give you instructions on tap and die making. This is a special branch of trade, and as a rule, it does not pay to make regular sized taps in the small quantities usually required in a shop. Special taps and dies can usually be made to advantage. We expect to have an article on this subject in a future issue. The portion of the question regarding space for chips, etc., was answered by question number 32 in the February issue. 2. Give proper angle of twist drills for cast iron, wrought iron, steel and brass ? A. The usual way of grinding for general work is to have the cutting edges at an angle of 6o degrees with the center line of drill or 120 degrees with each other this is used for steel as well as wrought and cast iron. For brass, many make the angle 45 degrees with the center line, or 4o degrees with each other, and this is occasionally used for soft cast iron. There is no fixed rule, and the cutting angles are varied in practice, especially where drills are ground by hand. C. 41. Subscriber asks: Will you give me some information con-cerning a good flooring for the ground floor of a machine shop ? The area of the floor is about 22,5oo square feet. The machines will be put on independent brick foundations. Information is especially desired about the method of building, cost, etc, of a floor of wooden blocks after immersion in tar. A. A good con-

. 38. B. R. A., Johnstown, Pa., asks how to calculate change gears for a lathe when it is compounded ? A. This was treated very clearly by W. L. Cheney, in the issue of February, 1895, and has been added to and made as complete as possible in ' Machine Shop Arithmetic," of which he is one of the authors. C. 39. N. J. A. W. asks the following questions: 1. What is the horse power of an engine 5 x 8 inches, plain slide valve, cut-off -a- of stroke, revolutions 240, boiler pressure, ioo pounds. 2. The horse power, with cylinder 5 x 8 inches, double ported balanced slide valve, cut-offs stroke, boiler pressure, 125 pounds. 3. The horse power of a tandem compound, cylinders 5 x 8 inches, stroke 48 inches, cut-offs stroke. 4. Also give the proportionate water consumption, full capacity. These are interesting questions, but they cannot be answered with much approximation to exactness. To do that a careful examination of the drawings must be made and everything per-taining to construction taken into account, as well as general arrangement. It it may be possible to get 20oâ€¢horse power from one engine, and quite impossible to get ioo horse power from another engine with cylinder of equal dimensions. More steam will go through a big hole than through a small one, and so on. If construction is good I should assume that the first named engine could be brought to develop 12 horse power, the second 15, and the third 20, but these figures have no special authority. As to the water consumption, I should assume that it would be about 4o pounds per horse power per hour, and that of the three engines the one named in the second instance would use a little the less. It has been assumed that all the engines are non-condensing. 0 H. 40. E. T., Philadelphia, Pa. : We do not know of any book which will give you instructions on tap and die making. This is a special branch of trade, and as a rule, it does not pay to make regular sized taps in the small quantities usually required in a shop. Special taps and dies can usually be made to advantage. We expect to have an article on this subject in a future issue. The portion of the question regarding space for chips, etc., was answered by question number 32 in the February issue. 2. Give proper angle of twist drills for cast iron, wrought iron, steel and brass ? A. The usual way of grinding for general work is to have the cutting edges at an angle of 6o degrees with the center line of drill or 120 degrees with each other this is used for steel as well as wrought and cast iron. For brass, many make the angle 45 degrees with the center line, or 4o degrees with each other, and this is occasionally used for soft cast iron. There is no fixed rule, and the cutting angles are varied in practice, especially where drills are ground by hand. C. 41. Subscriber asks: Will you give me some information con-cerning a good flooring for the ground floor of a machine shop ? The area of the floor is about 22,5oo square feet. The machines will be put on independent brick foundations. Information is especially desired about the method of building, cost, etc, of a floor of wooden blocks after immersion in tar. A. A good con- - X = P. For example take diametral pitch number = 4 to find the cir-cumferential pitch which will equal it, we have: 1 3.1416 = = = .7854 inch. N 4 If we now substitute this expression â€” for fi in equation (4 b) of the October number we have: 16.8 X P 7rXbXs â€” =_ and N = (6) N b Xs 16.8 X P and equation (4 c) becomes R-XsXn N (6 a) 16:8 x A the load P which one tooth will sustain is: zxbxs 16.8 x N The width of arm at center will be: W=A / TXbXo.9 1V a X thickness N Notations are the same as in the October number. As an example we will take a wheel of 20 inches diameter to transmit to HP. at 8o revolutions per minute. Taking A=18,o0o, we get for width of face of wheel: 126,000 X HP. = 126,000 x h= = 3 inches ; A X D i8,00ox2o and by (6 a): XSXn 3.14X 3,000 X 8o N= = 2.5 diam. pitch, nearly. I 6.8 x A 16.8 X 18,00o This gives for wheel of 20 inches diameter, 20 X2.5 = teeth. For width of arm at center: 3% inches, nearly. g sox4>< 3.5x0.9 2.5

MAKING JIGS. It is very often easy to devise jigs and fixtures for work, if the work to be held is uniform, as in cases where they are finished all over. But when dealing with rough castings it is much more difficult, as many a designer knows who has worked on the as-sumption that all pieces would be like the sample offered. The writer recalls a case of this kind which will be appreciated by many, where the designer was asked to get out a jig for a cer-tain casting, and after examining quite a number of them care-fully, he turned to the foreman with the remark : ' We'll either have to find a foundry that can give us more uniform castings, or else make a rubber jig." There are cases where this seems to be the only kind that will answer.