Microscope Museum

Collection of antique microscopes and other scientific instruments

 

    

Microscope 242 (unassigned maker; pillar-type linen tester; late 19th century to the early 20th century)

A picture containing cup Description automatically generatedA picture containing wooden, metalware Description automatically generatedA picture containing wooden Description automatically generatedA picture containing wooden, table Description automatically generatedA picture containing wooden Description automatically generatedA close-up of a gavel Description automatically generated with medium confidence

Microscope 242 is a linen tester, or linen prover, and should be dated from the late 19th century to the early 20th century. This instrument would be used for counting threads in fabrics (the number of threads per unit of length provides evidence of a higher quality of cloth). The earliest forms have a simple standard opening on the base, but later versions have an opening marked with calibrations of some kind. Microscopes 242 is a pillar-type linen tester. This is the most basic type of linen testers; the base has a single or more tiny pillars supporting the optics above (microscopes 242 has two tiny pillars arising from the base). 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 (for a signed folding linen tester see microscope 236) (Figures 1 and 2). Pillar-type linen testers were eventually supplanted by the folding versions and other types of thread counters in the early twentieth century.

 

Diagram, engineering drawing Description automatically generated

Figure 1. Folding linen testers engraved in the catalogues of several companies: (A) Palmer (1840); (B) Negretti and Zambra (1859); (C, D) William McAllister (1867); (E, F) Negretti and Zambra (1870s e 1885); (G) James Queen (1870 and 1872); (H) Ernest Goldbacher (1879); (I) B. Kahn & Son (c. 1890); (J) Bausch and Lomb (1892); (K) Arthur Thomas (1914); (L) Bausch and Lomb (1914); (M) A. Clarkson & Co (1920s); (N) Emille Deyrolle (1931); and (O, P, Q) Gallenkamp (c. 1939)

 

Figure 2. Pillar-type linen testers engraved in the catalogues of Palmer from 1840 (A) and Negretti & Zambra from 1859 (B) and from the 1870s (C)

 

References

LINEN TESTERS (OR LINEN PROVERS), AND THREAD-COUNTING MICROSCOPES: 19TH AND 20TH CENTURY (c. 1840- c. 1950) (https://www.microscope-antiques.com/linen.html), last accessed on 22.01.2022

FOLDING LINEN PROVER MICROSCOPES: 19TH AND 20TH CENTURY (https://www.microscope-antiques.com/foldingprovers.html), last accessed on 22.01.2022

PILLAR TYPE LINEN PROVER MICROSCOPE: 19TH CENTURY (https://www.microscope-antiques.com/pillarprovers.html#neill), last accessed on 22.01.2022

 

 

LAST EDITED: 12.03.2022