Substages. The substage is made in various forms in the different models. No. 29A has a 
simple tubular substage. No. 29B has a substage with focussing adjustment actuated by spiral screw, 
and which can be swung aside when not in use. No. 29C has a substage which is focussed 
by rack and pinion, and which also has an adjustment for centring the condenser or dark ground 
illuminator. No. 29D has a similar substage to No. 29C, but it has not the centring 
adjustment. No. 29E has a substage in which the apparatus is on dovetailed (Akehurst) fittings 
which slide into the substage and are clamped firmly into position by a screw. This method 
of changing the apparatus is very effective, and enables a condenser to be interchanged with a 
dark ground illuminator with ease, and with no derangement of the adjustments of the instrument. 
To facilitate this, the stage of the microscope on which this form of substage is fitted is cut away 
in the front, so that the condenser or dark ground illuminator can be withdrawn without altering 
the focussing adjustment of the substage. The substage is focussed by rack and pinion, but has 
no centring adjustment, the centring arrangements, when required, being on the slides themselves, 
so that each piece of apparatus can be individually centred. In model H the substage has a 
rack and pinion focussing motion and also centring adjustment. In addition the whole substage 
can be swung aside, out of the optic axis. This adjustment is most useful for removing the 
condenser when not in use and in facilitating the changing of substage apparatus. 
Nosepieces. Double, triple or quadruple nosepieces, can be supplied, of the dustproof 
pattern, so that the object glasses are protected from dust settling on their back lenses, if left on 
the microscope. 
Condensers of various types are supplied on these instruments. For general work Abbe 
condensers are fitted or for high power work achromatic condensers and dark ground illuminators 
are supplied. The latter should be used on the model with centring adjustment to the substage, or 
fitted with centring adjustments to slides for use with the Akehurst type substage. 
Object glasses and eyepieces. All object glasses and eyepieces are of our standard 
series, the performance of which has gained them a world wide reputation. 
Mechanical stage. On all models a detachable mechanical stage illustrated on page 84 
giving 1 in. vertical and 24 in. horizontal travel can be fitted. This stage is readily attached and 
detached. The mechanical stage has a pin which is inserted into a hole in the stage of the microscope. 
A clamp screw fixes the mechanical stage firmly in position, drawing it up against the back edge 
of the stage so that there is no tendency for it to shift its position once it is clamped. The movements 
of this mechanical stage are actuated by specially cut racks and pinions with fine teeth, giving a 
very delicate motion. In the Nos. 29F and G, a built-in mechanical stage of a new and simple 
type is fitted. This gives a travel in either direction of }in., and is of very robust construction. 
It will be noticed that the price of this mechanical stage is very moderate, and it is intended for the 
use of microscopists to whom a mechanical motion to the stage is necessary, but who do not require 
the large travel given by the detachable mechanical stage. The smaller amount of travel is 
sufficient for making blood counts and for the examination of mounted specimens, as it is seldom 
that more is required and the slide can be readily moved on the surface of the stage where 
different portions of the slides have to be examined in succession. Model H has a special form of 
mechanical stage built into the circular stage, of the pattern No. 3306 illustrated on page 84. 
Nos. 29 C and D can also be supplied with the No. 3515 stage described on page 84, this has 
a travel of 75 m/m. in the horizontal direction and 30 m/m. the vertical. 
Case. The instrument is supplied in oak case with lock and key, or for tropical climates, 
a teak case, specially screwed. 
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