ZOOLOGY AND BcjTANY, MIGKOSCOl-Y, ETC. 



101 



denced by fig. 19, aud of the second by the subsequent figures. To 

 attain the third a new and essentially more powerful arrangement of 

 arc lamp and reflector has been adopted. 



The body consists of an enclosed massive wooden box l"70m. high, 

 1 '70 m. long, and 70 cm. broad (fig. 19). It is supported on four fairly 

 strong and high feet. When the apparatus is out of action all the in- 

 terior parts can be kept away from external interference by storing them 

 in the lower part, which acts as a cupboard. The upper part of the body 

 is divided by a water-chamber, occupying almost the complete breadth 



Fig. 19. 



of the Ijox, and dividing it into two approximately cfjaal large parts. 

 The left-hand part is the lamp space with the reflector and its apparatus ; 

 the right hand is the projection-chamber with the optical accessories. 

 This bi-partition of the disposable space by means of the water-cham1)er 

 guarantees a coaiplete cooling of the whole apparatus. The water- 

 chamber contains about 25 litres of water, and is easily and quickly 

 emptied by means of a cock. A current of air entering at the floor of 

 the lamp-space, and issuing through an opening in the lid of the box, 

 increases the cooling efficiencv of the water. The lamp chamber is only 



