|
|
Microscope Museum Collection of antique microscopes and other
scientific instruments |
|
|
|
|
|
Microscope 300 (J Casartelli
& Son; cloth counting glass; early 20th century)
Guiseppe Luigi Casartelli
(1823 – 1900) emigrated as a child from Italy to Liverpool, England, joining
a relative’s scientific instrument firm business. He changed his name to
Joseph Louis Casartelli and later moved to
Manchester where he established himself as a manufacturer of optical
equipment, trading at 43 Market Street for many years. Around 1850, Casartelli produced microscopes, telescopes
and other optical devices. By the 1870s-80s, Casartelli’s
business focussed on supplying the heavy industries of Manchester, including
fittings for steam engines, mining equipment and optical instruments for the
fabric industry. One of Casartelli’s sons, Joseph
Henry, was made a partner of the company and the business became “J. Casartelli and Son” in 1896. Casartelli’s
business moved to 18 Brown Street, Manchester in 1922, acquired the business
of another family member in Liverpool in 1929, but was liquidated during the
Great Depression in 1933. Parts of the business continued under different
ownerships, including the Liverpool business as ‘J. Casartelli
& Son (Liverpool)’ (later ‘Casartelli
Instruments Ltd.’, in 1984, which closed in 1989), and the original business
became ‘J. Casartelli & Son Ltd.’ (and then
‘John Casartelli (M/c) Ltd.’ in 1939). Microscope
300 is a cloth counting glass engraved with ‘CASARTELLI, MANCHESTER’ and
should be dated to the early 20th century. This instrument
combines the advantages of the folding linen prover with the thread counter
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). The focus is
fixed, with a single combined scale, calibrated in 1/4-inch increments,
followed by 10 mm, calibrated in single mm. There is a pointer that moves, so
that the number of threads per unit of length can be counted. The lens is
suspended above the pointer. Similar instruments were sold by other firms
such as R & J Beck (Figure 1).
Figure 1. Linen prover as featured in a R & J Beck catalogue from the
1920s – 1930s. |
