Microscope Museum

Collection of antique microscopes and other scientific instruments

Microscope 287 (assigned to A Franks; pillar-type linen tester; late 19th century to early 29th century)

A. Franks Ltd was an optician and instrument maker which traded between 1879 and 1950. Founded in the latter part of the 19th century by Louis Aubrey Franks, they traded originally as 'L.A. Franks' from Manchester, listed as a manufacturer of photographic apparatus, optician and scientific instrument maker. Following a bankruptcy in 1879, a new firm was formed soon after, an optician trading as A. Franks. Microscope 287 is a pillar-type linen tester, or linen prover, and should be dated to the late 19th century to the early 20th century. These instruments would be used for counting threads in fabrics (the number of threads per unit of length provides evidence of a higher quality of cloth). Pillar-type linen testers are the most basic type of linen testers; the base has a single or more tiny pillars supporting the optics above. The basic form had a fixed focus, but focusing models were sold as well. Linen testers like these have been made and sold by many companies since at least the early 19th century and were rarely signed by their makers or retailers. This instrument is not signed but its original brass canister is engraved with ‘FRANKS’. Pillar-type linen testers were eventually supplanted by the folding versions and other types of thread counters in the early twentieth century.

LAST EDITED: 26.10.2022