9° 



Microscopical Essays. 



jett. It is true, it is precluded by it's form from fome of the 

 advantages of the two foregoing inftruments, becaufe both the 

 flage and the mirror are confined. 



This microfcope confifts of a large exterior body AB CD, 

 fupported on three fmall fc roles, which are., fixed to the ftage 

 E F ; the flage is fupported by three larger fcroles, that are 

 fcrewed to the mahogany pedefial G H. There is a drawer in 

 the pedefial which holds the apparatus. The concave mirror is 

 fitted to a focket in the center of the pedefial. The lower part 

 L M C D of the body forms an exterior tube, into which the up- 

 per part of the body A B L M Aides, and may be moved up or 

 down, fo as to bring the magnifiers, which are fcrewed on at N, 

 nearer to, or further from the object. 



TO USE CuLPEPERS MlCROSCGPE. 



Screw one of the buttons which contains a magnifying lens, to 

 the end N .of the body ; place the Aider, with the objecls, be- 

 tween the plates of the Aider-holder. Then, to attain diftinci 

 vifion, and a pleafing view of the objeB, adjuft the body to the 

 focus of the lens you are ufing, by moving the upper part gently 

 up and down, and regulate the light by the concave mirror. 



For opake obje&s, two additional pieces muff be ufed ; the firft 

 is, a cylindrical tube of brafs, reprefented at X, Plate IX. which 

 fits on the cylindrical part at N of the body ; the fecond piece is 

 the concave fpeculum H, Plate IX. this is to be fcrewed to the 

 lower end of the aforefaid tube : the upper edge of this tube 

 fhould be made to coincide with the line, which has the fame 

 a number 



