James Powell Swift learned his
trade while working with Andrew Ross. In 1854, he set up his own workshop at 15 Kingsland Road, London.
In 1870, he change his location to 128 City Road. The dating of this
microscope relies of the fact that he was located at City Road only for a few years,
1870-1872. He was thereafter located at 43 University
St. and by 1877, the firm was known as James Swift
& Son.
This binocular microscope
was specially designed for both conventional and
polarized light microscopy. The nosepiece has a Nicol
prism mounted above the Wenham prism with each residing
in a sliding brass box so that they can be introduced
or removed from the light path. This arrangement can
allow for simultaneous use of both prisms thereby
resulting in a stereoscopic image using polarized
light.
From the Swift catalog:
"Swift's Adaptation of the Analysing Prism
to the Binocular Microscope.
The advantages of
this adaptation, are effectual illumination in both
bodies, and (the analyser being placed above the
binocular prism) the transmission of a greater amount
of light, and less distortion consequent upon the
lessening of the distance between the objective and
binocular prism"
A specialize achromatic
substage condenser, described below, was designed for
this microscope.
Extracted from:
English Mechanic and Mirror of Science, Vol. 11,
1870 :
A short time since Mr.
James Swift, of the City Road, presented to the Royal
Microscopical Society an achromatic condenser he had
just completed, which has the advantage of containing
more accessories than any other piece of apparatus, as
Figs. 8 and 9 will show:
A, optical combination.
B, rack adjustment for focussing.
C, sliding frame with parts for dark ground illumination.
D, large diaphragm.
E, rotating cap to carry test stops.
F, small diaphragm of apertures.
G, polarizing prism.
H, selenite diaphragm.
I, oblique light shutter.