260 J. C. Draper—Projection of Microscope Photographs. 
lens formed of three sets of lenses and giving a perfectly flat 
rectilinear fie a, c,d, are mounted on a base board e, 
istance between d and ¢, required in giving the correct focus, 
may be obtained. The base e, f, is attached to a second or 
_ When a series of objects of very different sizes is to be pro- 
jected, as is the case with microscopic photographs taken under 
or ot 
objects as clearly visible at considerable distances as are the 
t. 
In closing this brief communication I desire is aaa that I 
have made phowenphs of Frustulia saxonica under a power of 
: ‘ he photographs in question were made 1n 
the City aa 2 building by a one-twentieth inch immersion 
e light was from the sun, reflected by a helio- 
stat, through ammonio-sulphate of copper solution, and con- 
