Pocket watch, circa 1600

Drawing of an antique pocket watch movement, from an 1891 encyclopedia. This type of movement, with a verge escapement and a fusee was used in watches from around 1600 to the early 1800s. Labelled parts, from accompanying text: (a) mainspring barrel, (b) fusee, (c) center (hour) wheel, (c') center wheel pinion, (d) third wheel, (e) fourth or contrate wheel, (f) crown wheel, (h) balance wheel (the pallets are also labelled h ), (i) minute hand, (j) hour hand, (k,l) cannon pinion, (m) minute wheel pinion, (n) minute wheel, (v) verge. Alterations to image: removed figure number, and converted to 32 greyscale PNG. Documented from an openly licensed real-object photograph on Wikimedia Commons; only the details stated by that source are recorded here. Remaining specifications are marked research required rather than estimated.