ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



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will be seen from fig. 42, the arrangement practically comprises a Van 

 Heurck camera, in which the solid body has been replaced by a conical 

 bellows, and the limbs elongated sufficiently to make the instrument 

 .completely independent of other supports ; while the Microscope-table 

 has become an integral part of the camera, and is lowered to such an 





Fig. 42. 



extent as to allow the operator to stand comfortably on the floor. This 

 camera-stand is placed on the floor, close to the laboratory table. An 

 approximately parallel beam of light is thrown across the lower shelf of 

 the instrument from an ordinary optical lantern occupying a low inde- 

 pendent stand, and from which the projection front has been removed. 

 The most satisfactory light-source was found to be the oxy-hydrogen jet, 

 but an incandescent gas-burner is good for at least the lower powers. 

 The total height to the focussing screen is 46 in. but could be varied 

 to suit different observers. From the eye-piece to the sensitive plate 

 is 24 in. The top is a square of 12 in. side with a centre fitting for a 

 April 15th, 1903 q 



