271 
is set at a certain angle. It is not, however, always conve- 
nient to use the microscope at one definite inclination, and 
for this reason I think that the instrument about to be 
described will commend itself, since it can be used with the 
greatest ease whatever may be the angle at which the 
microscope is inclined. It has also the advantage of being 
simple in construction, and consequently inexpensive. 
This apparatus is, as will be seen, a modification of the 
steel disc of Soemmering,! and the neutral tint reflector 
described by Dr. Lionel S. Beale.2 It consists essen- 
tially of a reflector, which can be inclined at any angle; 
and when set for drawing, is used in exactly the same way 
as the camera lucida. The arrangement will be best under- 
stood by reference to the accompanying figures:—(a) is a 
silver or steel reflector, the upper edge of which is made thin 
like a knife blade, as indicated in fig. 3, so that the view of 
Hie. 
Tm 
the pencil used in drawing may not be interfered with. 
1 Vide Dr. Carpenter, ‘The Microscope and its Revelations,’ 4th edition, 
p- 100. Bi 
2 «How to Work with the Microscope,’ 4th edition, 1868, p. 27. 
