Compound achromatic student microscope






United Kingdom


J. Salmon & Son / Makers / 4 Seymour St. / Euston Sqre / London N.W.



Optical 1


Optical 2


Size of the box (h x w x d)

39 × 22 × 20.1 cm

Size of the microscope (h x w x d)

34 × 11.8 × 17 cm

Inventory number

SM 26


The microscope is kept in a wooden box with three drawers.
It is a simple student microscope with an ‘English foot’, mounted on a wooden board which slides into the box. The upper part of the microscope is mounted between trunnions. Coarse adjustment is by rack and pinion, fine adjustment by means of a lever acting on the nose piece. The circular stage has a simple mechanical attachment. Below the stage a rotating stop with four holes. There is a concave mirror in a bracket.
Accessories are a bull’s eye condenser on a stand for incident light and a live box.
The Huygenian eypiece has a focal length of 36.2 mm, its magnification is 6.9×.
The objective lens has a RMS thread, it is marked ‘weak’ and ‘strong’. There are three combinations possible. It was measured on its own microscope.

Objective 1 1+2 1+2+3
Focal length (mm) 18.55 9.54 7.23
Magnification 45.92 93.48 129.5
Numerical aperture 0.088 0.18 0.25
Resolving power (µm) 4 2.5 1.75
Star test coma coma coma