tfhe Microfeope explained. ix 
of northern latitudes in the winter, is fo near the horizon, 
and more efpecially when the fun is dire&ly perpendicu¬ 
lar to the front of the room, it cannot then form a fpot 
of light perfe&ly round j but if the fun be on either fide 
of that perpendicular, a round fpot may be obtained. 
The moft ufeful magnifiers in the folar microfeope, 
are the fourth, fifth, and fixth. 
Care muft be taken to pull out, or thrufl back, the 
tube I more or lefs, as the objeT is capable of fuftain- 
ing the fun’s heat, fo that the fpot of light may be 
broad enough to cover the obje< 5 l. Dead bodies may be 
placed within about an inch of the focus of the double 
convex lens, which diflance mull be shortened for liv¬ 
ing creatures, or they will foon be killed. 
If the light falls not exa&ly right, you may eafily 
diredl it thro’ the axis of the microfcopic lens ; and 
there keep it during the time of your examination, by 
the help of the fcrews f and e, by following the fun’s 
motion. 
Having taken notice of a fcreen to throw the images 
of objects upon, fuch a fcreen is ufually made of a flieet 
of the largeft elephant paper, {train’d on a frame, which, 
hides up and down on a round mahogany pillar, in the 
manner of fome fire fcreens. A larger fort are compofed 
of feveral fheets of the fame paper palled together on 
cloth, and let down with a roller from the ceiling in the 
manner of a large map. 
Fig. S. which is feen below the figures 4 and 5. 
reprefents that additional part of a folar microfeope, 
which is defigned for the examination of larger trans¬ 
parent objects, than can be contained in the apparatus 
already deferibed, and is called a magellefcope. 
When this is to be ufed, unferew the cap TV, from 
the inward hiding tube I, and ferew the apparatus S in 
the place of it, the hiders for this purpofe are made of 
mahogany as W, with three large round holes, each 
furnifhed 
