Microscope Museum

Collection of antique microscopes and other scientific instruments

Microscope 471 (Thomas Armstrong & Brother; thread counter, c. 1910)

In 1825, Joseph Armstrong started a business as jeweller and silversmith at 261 Deansgate, Manchester. After Joseph died in 1851, his elder son Thomas continued managing the business, which was expanded to manufacture spectacles and optical instruments. In 1868, Thomas took his brother George in partnership and the firm was renamed as Thomas Armstrong & Brother. The company grew considerably between 1877 and 1891, employing 15 people including Thompson and George’s younger brother Alfred. Around 1887, the company acquired additional premises on St Mary Street. Towards the end of the 1890s, Thomas’s son, Frank Armstrong, also started working in the company, which expanded further into Liverpool in 1904 with the opening of a branch at 112 Bold Street. In the meantime, the company’s headquarters in Manchester moved to larger premises at 78 Deansgate. In 1920, the company was sold to Leonard Douglas Kidson, of 1 Booth Street, Manchester, but Frank Armstrong continued with the company for a further 10 years. In 1965, the company was taken over by Harrisons Opticians, which, in 1968, was taken over by Dollond & Aitchison, which itself was absorbed into Boots Opticians in 2009. Microscope 471 is a thread counter. The instrument is not signed but came into its original signed box marked with “Thomas Armstrong & Brother, Manchester & Liverpool”. The instrument should be dated to c. 1910 and would be used for counting threads in fabrics (the number of threads per unit of length provides evidence of a higher quality of cloth). This instrument contains a scale along which a pointer moves so that the number of threads per unit of length can be counted. The lens is suspended above the pointer and moves via a screw.