Outfit for Ultra Microscopy. 
This is mounted complete on an 
optical bench consisting of a 
strong steel bar (A) 24 in long, 
carried on 2 cross bars (B), sup- 
ported on 2 levelling screws (C). 
Projecting over one end of the 
bar is fixed an automatic arc lamp 
(D) 5 to 10 amps, which has the 
positive carbon (E) horizontal 
and the negative carbon vertical. 
The crater of the arc is thus direct- 
ly facing the optic axis of the 
bench. The arc lamp is enclosed in a lamp house (F) with side doors and with a small! tubular 
aperture (H) in the front to allow the light to emerge. The lamp is also provided with raising 
and lowering motions (G) and a small lateral movement swinging on the pivot (K). A series of 
fittings slide along the steel bar. The first (L) carries an achromatic lens system for focussing 
an image of the crater of the arc upon the fitting (M) carrying an adjustable slit which is provided 
with a rotating movement and side cheeks for limiting the length of the slit. A fitting (N) carries 
a 32 m/m achromatic lens system by which an image of the slit is projected along the optic axis 
5 times smaller than the slit. At a distance of about 280 m/m from this lens system a special 
microscope object glass, 25 m/m focus, .28 N.A., is carried upon another fitting (O). This object 
glass has a working distance of 9 m/m and allows of the use of the highest power lenses without 
touching the mount of the observing lens. Between the slit and the projecting lens an adjustable 
chisel edge is carried on the fitting (P) by which the beam of light can be restricted in height. The 
adjustments having been made on the optical bench to ensure proper centring the whole bench 
can be adjusted vertically by the front levelling screw (C) and laterally by moving the whole bench. 
The levelling screws stand on 3 smooth metal plates, the front one (R) of which is provided with 
a lateral screw adjustment. The size of the final ribbon of light can be varied by arranging the 
optical elements in different positions. 
No. 3380. Ultra microscopic outfit ac a: ac: a's ae ae 1 LOO = Ol Og 
No. 3381. Holder for fluids Bee ss se soa Price according to model. q 
No. 3016. Aquarium microscope. This 
instrument consists of a joint- 
ed arm moving parallel to the 
side of an aquarium and carry- 
ing an aplanatic lens. The arm 
is focussed by means of rack 
and pinion which is fixed to 
a wooden stand on which the 
aquarium is placed. Without 
aquarium, with one achro- 
maticamagniticrs <> or <12 458° 0 
No. 3016A. As above but with a single lens magnifier instead of achromatic... con Sle | 
No. 3017. Aquarium, 6! 5x1} in. 0 5 64 
