BAIRD & TATLOCK (LONDON) LTD. 



461 462 463 



461 T Microscope Lamp, Dr. Lassar's, for gas, on adjustable stand 



464 

 each 1 15 



462' Microscope Lamp, Dr. Lassar's, for petroleum 



463' " Nernst " Electric Lamp (new form), specially designed and patented by J. E. Barnard, 

 Esq., F.R.M.S. 



This lamp is designed to give an evenly illuminated field in the microscope, without giving an 

 image of the incandescent film, which is common with every other form of electric microscope 

 lamp. This is effected by the light from the incandescent filament falling upon an optically worked 

 slab of opal glass fixed at an angle of 45 to the axis of the filament. The light so obtained resembles 

 white-cloud illumination, and the bull's eye condenser, which is indispensable with ordinary lamp 

 illumination, becomes unnecessary. The lamp is fixed on a swivel, and can be placed at any angle, 

 and can be raised and lowered at will ; provision is also made for taking tinted glass light filters. 

 The J-ampere lamp supplied gives more than sufficient light for a ^,-in. oil immersion lens. 



The current consumed by the " Nernst " lamp is 50 per cent, less than with the ordinary incan- 

 descent lamp. 



The lamp was originally designed by the inventor for the Laboratories of the Lister Institute 

 of Preventive Medicine, Chelsea, and it has also met with much favour in other laboratories. Intend- 

 ing purchasers, when ordering, must give the voltage of their current, and whether cylindrical 

 or forked wall plugs are to be supplied. 



METHOD OF USING THE LAMP. 



If the microscope is used in the vertical position, the flat top of the lamp should be tilted until 

 it is parallel with the stage of the microscope, at the same time the lamp should be brought fairly 

 close to the instrument. If the microscope is inclined, the top reflecting surface of the lamp should 

 be tilted to bring it to the same angle as the stage of the instrument. 



Price of the lamp, for use with current of 150 to' 200 volts only . . 



each 2 



464 s Microscope Lamp, with small incandescent mantle, glass globe, and metal chimney as 

 devised by Dr. Paine ; mounted on metal sole with control tap . . . . each 



5 



CROSS STREET HATTO1ST GARDEN, E-C 



