Image: Going barrel

Description: Drawing of a 'going barrel' type mainspring barrel in a watch, sectioned through the axis. The mainspring is shown fully wound, tight around the winding arbor. The wheel attached with screws at top is the ratchet, to prevent the mainspring from unwinding. This was from a keywind pocketwatch; the winding arbor (axle) extended to a squared off section (not shown) accessible through a hole in the back. A key was inserted through the hole, fitted on the shank, and turned to wind the watch. Besides the arbor, this is similar to a mainspring barrel in a modern watch. Alterations: removed caption, sharpened, converted to PNG.
Title: Going barrel
Credit: downloaded from Britten, Frederick J (1896) The Watch and Clock Maker's Handbook, Dictionary and Guide, 9th Ed., Spon & Chamberlain, New York, p.236, fig.14 on Google Books
Author: Frederick J. Britten
Permission: Public domain - published in the US before 1923
Usage Terms: Public domain
License: Public domain
Attribution Required?: No