ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



311 



kerosene to become dangerously hot. The lamp is filled at F with a 

 curved glass funnel ; and the two flat wicks, 1^ in. broad, are 

 turned by their separate keys outside the pipe. The pipe has two 

 elbows, which conduct heat and smoke away, and completely cut off 

 the light from the top of the flame. These elbows may be rotated 

 into any convenient position. Opposite the lamp-chimney a third 

 short elbow E is inserted, closed by a movable cap. Through this 

 elbow the chimney can be removed, the wicks trimmed, and a concave 

 glass or tin reflector M, 4^ in. in diameter, may be placed behind 

 the flame. The flat of the wicks should be parallel to this mirror. 

 Opposite the mirror, and directly in front of the flame, a plano-con- 

 vex lens X, 2 in. in diameter, is inserted in a hole in the pipe. The 



Fig. 62. 



light reflected from the mirror M passes through this lens, and falls 

 upon the mirror of the Microscope, whence it illuminates the object 

 upon the slide in the ordinary way. The object is magnifled by a 

 1/5 or 1/2 in. objective ; the eye-piece is removed; and the image 

 is projected upon a ground-glass screen G, 1^ ft. square, which is 

 placed from one to four feet in front of the Microscope. The screen 

 is supported by a perpendicular iron rod and cork-lined clamp, such 

 as is in use in every chemical laboratory, to hold glass retorts, tubes, 

 &c. The iron rod rests upon the floor, occupies very little space, and 

 can be moved to any convenient focusing distance. A similar stand 

 supports the horizontal elbow of the stove-pipe. The body-tube 

 should be blackened inside as in photo-micrography. 



The great difficulty with the apparatus consists in trying to pre- 

 vent the reflection of superfluous light. To obviate this, a pasteboard 

 box B, 6 X 6 X 8 in., is readily cut to fit closely over the piano- 



