No. 22 London Microscope. 
The No. 22 London microscope is an instrument of strong construction and with adjustments 
suitable for all general purposes, for teaching establishments and medical work. It is convenicnt 
in use and the manipulation is simple, as the adjustments are confined to those which are necessary 
for the work for which it is intended. 
The following is a specification of the instrument:— 
Base, pillar and }imb. The base and pillar are in one heavy iron casting. The base hasa large 
spread, making the microscope stand firmly, either in the vertical, inclined or horizontal position. The 
limb is hinged into the top of the pillar, so that the microscope can be used at any angle, from the 
vertical to the horizontal. These parts are finished in stoved black enamel, which withstands the 
action of acids. 
Stage. The stage is large, measuring 4 in. x 3% in., and is therefore of a sufficient size 
to permit of a petri dish or culture plate being placed upon it. It is of solid construction, and rigidly 
attached to the limb of the microscope. 
Focussing adjustments. The microscope has a coarse adjustment, actuated by helical 
rack and pinion. The greatest care is taken in the perfect smoothness of working of the slides in 
which the body moves, so that any shake or backlash is obviated. Comparatively high powers can 
be focussed with it. The fine adjustment is of a simple but very strong and effective design. It 
is constructed in such a manner that a smootb working focussing adjustment giving no backlash is 
obtained. It is actuated by a large milled head, giving a sufficiently delicate movement for use 
with an oil immersion object glass. It is readily accessible to either hand, a quality which every 
slow motion should possess. 
Body tube. This is of the standard length and has an extending drawtube, marked so 
that the tube length can be readily set at 160 m/m., for which the object glasses are corrected. 
Mirror. A double mirror, plane and concave, is fitted into the lower end of the limb. 
It is in a semi-circular fitting which rotates, and in which the mirror turns on its axis. 
Substage. The simple form No. 22A has no substage but a revolving dome shaped diaphragm 
with a number of apertures of varying sizes can be supplied. The No. 22B has a substage, which 
is focussed by a spiral screw, and which can be swung aside when not in use. The No. 22C has 
a complete substage, focussed by rack and pinion and provided with centring adjustment. This 
substage can also be swung out of the optic axis of the microscope. 
Nosepieces. Double or triple nosepieces of the dustproof pattern, can be supplied, so that 
the object glasses are protected from dust settling on their back lenses, if left on the microscope. 
Condenser. We supply the Abbe condenser on these microscopes, or on the Model No. 22C, 
with centring substage, an achromatic condenser can be fitted. 
Object glasses and eyepieces. All object glasses and eyepieces are of our standard series, 
the performance of these has gained them a world wide reputation. 
Stage clips are fitted to the stage for holding specimens in position. 
Mechanical stage can be fitted, the pattern being illustrated on page 84 (No. 3305). 
Case. The instrument is supplied in either a stiff canvas case with carrying handle, or oak 
or polished mahogany cabinet, as specified in price list. 
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