“To use the saw, one end is removed from the hooked handle, and the carrier needle, armed with a strong thread is attached to this end;  the needle is passed under the bone, and the saw drawn into position with the cutting edge upwards.  The operator, grasping the handles, draws the saw alternately from side to side until the bone is divided.  There is great danger of breaking a Chain Saw if it be worked carelessly; it should be drawn from side to side steadily, at an angle of 45 degrees to the axis of the bone.  An improvement whereby the rotates about a socket made of two haves, joined by a ring, the one half bearing an impression of a chain link allows for continued use of a broken chain.”   Aloe- 3850