Antique brass Watson microscope objective
Marked '1/6 IN.' '0.87 N.A.'
'W. Watson and Sons, London'
RMS thread.
A very attractive objective by this famous maker. A super golden brown and hardly marked lacquer.
Front element bright, some surface pitting mainly to edge which doesn't markedly affect performance.
Optics look bright when inspected with phase telescope.
A high NA of 0.87. Mag is ca. 38x on a 160 mm tube and a competent performer for its age. Image below of test diatom Pleurosigma angulatum (NBS slide)
showing punctae with deep blue filter and oblique lighting.
UK shipping £1, elsewhere £2.