Page 10-11 AMERICAN MACHINIST 1912, The History of the Drill Press, chapter 9.

March 8, 1912.

Buying--AMERICAN MACHINIST--Section Vol. 46, No. 10

After the Strap Drill Came the Bow Drill Chapter-9

WHEREAS
the Strap Drill usually depended upon hand pieces, (often the teeth of a bear), attached to the ends of the thongs, to facilitate the pulling, the Bow Drill marks a step in advance in the art of drilling, due to the mechanical principle of the bow.

The Bow Drill consists of four parts-the shaft, the headpiece, the bow, and its strap. Except for the bow it is identical with the Strap Drill. The U. S. National Museum contains a great variety of Bow Drills, gathered chiefly along the Alaskan Coast.
The simplest of Bow Drills are those from Alaska, which are made from the ribs of deer, and are about 18 inches long,
seven-eighths of an inch broad and one-fourth of an inch thick, upon which are carved animals or men not unlike certain carvings from the caves of France.

There is much to be said regarding the Bow Drill, and the various points will be taken up in order. The picture on this page (which is a photo-graph of one of the wax figure life-size exhibits in the American Museum of Natural History, New York City) illustrates a common use of the Bow Drill by an Esquimo. Note that the shaft is held by a mouthpiece, held between the teeth of the operator.., The jar on the teeth, caused by this method, naturally must • be anything but pleasant.

Today 19121 24 to 42-in. Heavy Pattern Upright Drilling Machine The spindle has eight speeds, a ball thrust bearing and a quick advance and return. It is made of high carbon steel, is counter-balanced, and is driven by gears which are planed theoretically correct. The Frame consists of a deep generously ribbed base, a large accurately ground column, a shape-ly gear guarded yoke, a stiff well placed back brace, and a simple conveniently located belt shifter.

CINncinnati 4, 5 and 6-foot Regular Plain Radial Drilling Machines
Renewable bronze bushes are used through-out the entire machine with the exception of minor feed works bearings. Many of them have flanged ends of generous proportions to support the ground hub surfaces of the gears. ' The head is of unusual construction completely enclosing its gearing, affording protection to the operator and eliminating dust and grit from its working parts, is narrow gibbed on arm and freely adjusted.


.