94 



PRACTICAL MICROSCOPY. 



ball-and-socket joint. A brass tube slides on the vertical 

 rod bearing the condenser and lamp with neutral tint shade 

 and " white cloud " reflector having telescope and clamping 

 screw adjustments. When these are placed in any desired 

 relation to each other, the whole can be vertically adjusted 

 by a rack and pinion with the greatest accuracy. Its price 



is five guineas. Another 

 beautiful lamp has been 

 made by Messrs. Wood, of 

 Liverpool, for Messrs. Dallin- 

 ger and Drysdale. These 

 two observers, whilst work- 

 ing at the life-history of the 

 monads, appreciated the diffi- 

 culty of accurately centering 

 the image of the flame when 

 working with the Jy and ^ 

 objectives, and so devised 

 this lamp, which is illustrated 

 in the April number of the 

 'Monthly Microscopical 

 Journal' for 1876, vol. xv. 



Parkes' microscope lamp 

 with cooling evaporator may 

 be seen in Figs. 84 and 85. 



C is a bronzed copper cylin- 

 FIG. 84. , . . , , , ' 



dncal shade 3^ inches m 



diameter with a hood at the front to prevent the upward 

 reflection of light. At the back is a parabolic reflector 

 transmitting nearly parallel rays, made removable for the 

 purpose of cleaning. At the front is a tinted " light-modi- 

 fier," secured by a bayonet joint, and may be also removed 

 when desirable. D is the " cooling evaporator " ; a layer of 

 thick felt is placed inside for saturation. When the lamp is 



