Alexander Cumming hand microtome, 1770.

A microtome is used for cutting thin slices of samples for microscopic investigation. Alexander Cumming, a watchmaker of King George III, invented and manufactured this device. The sample is placed in the hole and is pressed upward by a screw from the bottom. Slices of the sample were obtained with a razor in which the top was pushed to the required amount by the screw. Although the adjustments were for 1/500, 1/750 y 1/1000 part of an inch, the instrument could not really achieve this degree of accuracy. Currently, what known as hand microtome, have not had substantial variations, the principle remains the same, they are still marketed and used in the field of education.