66 



TPIE AMERICAN MONTHLY 



[March, 



reception of the lens. Both of these arms are movable, but the upper 

 one should remain fixed. Moving the other will focus the rays of 

 light and make larger or smaller i^epresentations of the preparation 

 according to its distance from the object-bearer. The light used may 

 be either sunlight or artificial. 



As a rule, an ordinary lamp, with or without a small reflector, 

 answers all purposes. The light being placed in the proper position, 

 and the preparation to be drawn on the object-table, a sharply outlined 

 picture of the preparation will be thrown on a piece of drawing-paper 

 beneath. By regulating the height of the arm bearing the lens, or by 

 changing the lens, any magnification between two and fifteen times can 

 be made. 



In this way the outlines of an absolutely true drawing can be made 

 and the details filled in from the microscope, or a precise picture can 

 be made from the apparatus alone, so sharply defined is the representa- 

 tion. 



Of course specimens colored with dark stains give more clearly dif- 

 ferentiated pictures than the light ones. 



The instrument is made by Meyrowitz Brothers, of New York, to 

 whom we are indebted for the cut, and may be had with two or three 

 lenses. Two are all that are necessary ordinarily, but the third is im- 

 portant sometimes when the object to be drawn is ver}- small. 



Continental Apparatus in England. — The French and German 

 instruments and objectives were first brought into England because 

 they could be obtained for about one-fourth the price exacted at that 

 time by English makers for instruments of no greater practical value. 

 English dealers (not the great makers) were in the habit of taking 

 inferior objectives which had been rejected by their makers, and selling 

 them as their own make at higher prices than would suffice to purchase 

 first-class glasses from the Continental firms themselves. — Ray Lan- 

 kester in Nature. 



