Gear's illustrated catalogue of wood and iron working machinery (1872)
A.S. Gear, Gear, A. S · Boston : Printed at A.S. Gear's printing office, 62 Sudbury Street · leaf 466
The attention of Watch buyers is called to the fact that the Elgin Watches now offeretlhave, with other improvements, a new so constraoted as to enclose the works, andform a protection against dust, enabling themovement to remain in order without cleaning double the time that a Watch will…
