ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
89 
with sprung guides moving in grooves at the sides of the stage ; small 
clips are applied for use in the horizontal position. The Mayall 
mechanical stage can be applied if required. The sliding-bar carrying 
the substage is specially wtdl fitted so that a condenser of fairly largo 
aperture may be focused, and a clamping screw fixes it in position. The 
substage has mechanical centering movements, and an iris-diaphragm. 
The mirror is removable in case it may be desired to work with direct 
light from the lamp. 
We are requested by Messrs. Swift to note that at a small additional 
cost they can apply a rack-and-pinion instead of the sliding movement 
to the substage. 
Mason’s Improvements in Oxy-hydrogen Microscopes.*— Mr. R. 
G. Mason, of 69, Clapham Park Road, Clapham, S.W., has introduced 
the above form of lantern and table Microscope, a patent for which has 
been applied for. Until the present time the lantern Microscope has 
been a distinct instrument from the table form of stand. By the union 
of the above parts an instrument is obtained that, when not in use for 
Fw. 2. 
Fig. 3. 
screen projections, can be easily altered, 
as shown by fig. 3. No unscrewing is 
required, and there are no loose parts. 
Fig. 2 shows the instrument as used on 
the lantern. It is very convenient for 
the science teacher or general lecturer, as 
a demonstration may be made to either 
a small or large audience with equal 
facility. The lower part, which carries 
the joint for inclining the instrument at 
any angle, is fitted with concave and 
flat mirrors on swinging arm, also with the universal size substage fitting 
tube for apparatus. The body and draw, which fits into the upper part, 
is of large diameter, and is screwed with the Society’s size screw, thus 
enabling any ordinary microscopic objective to be used with it. It is 
fitted with a first-class rack, and also screw fine motion working steadily 
under high powers. This fine motion is especially useful in photo- 
micrography. The stage being of the usual form, both object and 
objective are in view, and easily manipulated while in use, thus doing 
away with an objection that is often present in the older formsjof lantern 
* Engl. Mech., lii. (1890) pp. 306-7. 
