No. 3404. Slide with silver film, with fine pinholes under cover glasses of 
three different thicknesses 
No. 3404A. Simple form with only one thickness of cover glass 
No. 3379. Apertometer ... 
No. 3385. Brass diaphragm for 
use in eyepiece with 
above ... 
No. 3665. Tube length corrector 
£0 12 
TD 
for) 
6 
0 
This appliance, designed by the British 
Scientific Instrument Research Association, screws 
into the nosepiece of the microscope above the object glass. It consists of two fully corrected 
optical systems, the separation of which can be varied by turning a milled ring. It has the effect 
of altering the tube length for which an object glass is corrected without impairing its optical 
proper ties. 
No. 3358. Iris diaphragm to screw into nosepiece of microscope to reduce aperture 
of object glass ons : 
that object glass can be rotated on its axis 
ri I | No. 3356. | Nosepiece to screw into microscope body so 
No. 3349. Super eyepiece carrier to fit drawtube of 
microscope which will carry Ramsden eye- 
piece for observing and measuring eyepoint 
No. 3349A. Ramsden eyepiece x8 to fit above . 
No. 3349B. Micrometer to fit on front of Ramsden eye- 
piece No. 3349A 
No. 3355. Adapter to fit into nosepiece of micro- 
scope with slide for carrying stops and 
patches, including a series of circular 
patches and stops, and diaphragms of 
various shapes i 
2 
). 33855A. Adapter to fit into nosepiece of micro- 
scope with slide carrying a series of low 
No. 3355. power lenses for altering the tube length 
correction of object glasses 
No. 3160. Barnard interferometer plates for 
testing mechanical defects; one plate 
is mounted to screw into the body of 
the microscope like an object glass ; the 
other is on a levelling plate to stand on 
the stage aie a 486 
No. 3160. No. 4481. Cube of Uranium glass, side -5 in. 
78 
£0 16 
2 10 
0 
6 
