QUARTZ MERCURY VAPOUR LAMP. 
This lamp consists of a K.B.B. atmospheric 
type quartz mercury vapour burner, in a convenient 
housing for use as a microscope illuminant. It has 
a condenser which can be focussed, an iris diaphragm 
and screen holder. The condenser is made in glass 
or quartz. The back plate of the housing can be 
removed so that the lamp can readily be employed 
for other purposes. The lamp can be operated from 
a direct current house supply with a suitable resis- 
tance, or from alternating current with a rectifier or 
motor generator. 
The quartz mercury vapour burner gives an 
illumination with a small number of monochromatic 
spectrum lines, and by the use of filters any one of 
these lines can be used giving a monochromatic 
source of light of great intensity. In addition to 
the advantages offered in the visible spectrum the No-s = 
burner is also one of the richest sources of ultra-violet radiation, and since quartz is transparent to 
rays of very short wavelength, the burner is particularly valuable to research workers requiring 
light in the ultra-violet and ‘extreme ultra-violet region of the spectrum. 
The housing can be supplied for existing burners. For this purpose it is necessary for the burner 
to be sent to us, and a small charge is made for the necessary fitting. 
No. 3615. Quartz mercury vapour lamp, complete ... a — sec L200 OR 0a 
No. 3616. Resistance for low voltages. oes Be ore ae me me 2 0F 
No. 3617. Resistance for high voltages. ae on a bs! Aw on see) Oh] 
No. 3618. Housing only... sia : wee 810 OF 
No. 3619. Hewittic rectifier, for operating burner on alternating current. se 6 LORTOOF 
No. 3620 Quartz condenser ... Soh ee es cae ass tr Sac 1 10-04 
No 3327. Didymium glass screen. ... ae ae ae yee oe ere aes OSI} 
CORNEX MICROSCOPE ARC LAMP. 
This lamp is specially suited for photography, high 
power dark ground illumination or for work where very 
deep colour filters are employed. It is supplied either with 
hand or clockwork feed. This latter moves the carbons 
at the approximate speed at which they burn away, although 
a slight hand adjustment may be necessary to compensate 
for an irregular burning of the carbons. The lamp burns on 
4 to 5 amps. and on direct or alternating current. For direct 
current 6 m/m. and 8 m/m. carbons are used, and for alter- 
nating, 7 m/m. carbons. 
A condensing lens is provided by means of which the light 
may be made parallel or convergent. 
This lamp, with a quartz condenser, is of special use 
for fluorescent work in conjunction with screens or a mono- 
chromator to cut out the visible light. 
No. 3636. No. 3635. Cornex arc lamp with clockwork feed {£7 15 0O 
No. 3636. Cornex arc lamp with hand feed 410 0 
No. 3643. Quartz condenser in place of glass condenser a aoe gs Soe Onl OmaG 
No. 3637. Adjustable resistance for voltages 100—250 D.C. or A.C. 2 2 0 
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