In the early 1850s, a banker named W. Peters invented a device capable of microscopic writing or engraving. There are only a relatively few slides (example shown bears the date Mar. 10th 1854) that were produced during that early period on the Peters Machine, mostly by R. J. Farrants. This unusual type of engraved slide became more popular during the International Exhibition of 1862 when W. Webb introduced and demonstrated his new engraving machine, continuing to produce and sell his slides commercially until at least the mid 1880s. These slides are usually of short religious texts or well known maxims, and occasionally, geometric figures. A number of individuals also offered slides with ruled lines engraved at so many lines per inch or millimeter, to be used as stage micrometers. Very finely ruled slides were produced by only a few individuals (F.A. Nobert probably being the best known) and were used to test the resolving power of objective lens systems. Also quite rare, are examples of intricate geometric scroll patterns engraved on glass slides by W. Teasdale, using a pendulum vibrating in a compound manner.  Images below are from the slides shown.