False colour scanning electron micrograph (SEM) of the movement of an inexpensive watch (made by Timex) showing a close-up of the minute wheel & pinion (bottom) meshing with the hour wheel (top). These comprise part of the motion work of the watch, the train of reduction gears that display the time. A central wheel, connected to the teeth of the barrel (which houses the mainspring) turns once per hour. The no. of leaves & teeth in the minute/hour wheel reduction gives a ratio of 12:1, ie 12 revolutions of the centre wheel will display 12 hours. Magnification: x 8 at 35mm size. Original is bw print h100/164