ZOOLOaY AND BOTANY, MIOKOSCOPY, ETC. 



125 



Nelson's Microscope Lamp. — Mr. E. M. l^elson some time ago 

 devised the lamp shown in fig. 25 ; but no description or figure of it has 

 been issued till now. The principal points in the design are (1) that 

 the flame (using either the edge or the broadside) can be brought much 

 nearer to the surface of the table than usual, which is secured by- 

 making the oil-well very shallow, large enough however to hold 



Fig. 25. 



sufficient for eight or nine hours' work, and with means for replenish- 

 ing the supply of oil without touching the flame ; (2) the metal 

 chimney is arranged to cut off all the light except that required for 

 actual use with the Microscope, and the only glass required is an 

 ordinary 3x1 slip which slides in a groove about an inch in front 

 of the flame and can be readily removed for cleaning ; (3) the conden- 

 sing lens is of the compound Herschellian form, by which a clearer 

 disk of light can be obtained than with the usual bull's-eye, and is 

 provided with means of adjustment in all directions. The lamp was 

 constructed bv Messrs. Swift and Son. 



