THE MICROSCOPE: CHARLES SINGER 59 



luckily put them in the ends of a tube, and thus the first tele- 

 scopes were made." Metius also applied for a patent, and £u copy 

 of his application has survived among the MSS. of Christion Huygens 

 (1629-1695). 



(14) Galileo (1564-1642) was the effective discoverer of the micro- 

 scope, a discovery which, as in the other cases, was bound up with 

 that of the telescope. The event may be referred to the early part 

 of 1609, and the story may be told in a translation of his own 

 words : — 



" About ten months ago," he says, " a rumour reached me of 

 an ocular instrument made by a certain Dutchman by means of 

 which an object could be made to appear distinct and near to an 

 eye that looked through it, although it was really far away. . . . 

 And so I considered the desirability of investigating the method, 

 and I reflected on the means by which I might come to the inven- 

 tion of a similar instrument. A little later, making use of the 

 doctrine of refractions, I first prepared a leaden tube, at the ends 

 of which were placed two lenses, each of them flat on one side, and 

 as to the other side I fashioned one concave and the other convex. 

 Then, moving the eye to the concave one, I saw the objects fairly 

 large and nearer, for they appeared three times nearer and nine 

 times larger than when they were observed by the naked eye. Soon 

 after I made another more exactly, representing objects more than 

 sixty times larger. At length, sparing no labour and no expense, 

 I got to the point that I could construct an excellent instrumeno 

 so that things seen through it appeared almost a thousand times 

 greater and more than thirty-fold nearer than if observed by the 

 naked eye." (Siderius Xuncius, Venice, 1610). 



In another work he says : ' ' Some would tell me that it is of 

 no little help in the discovery and resolution of a problem to be 

 first of all in some way aware of the true conclusion and certain of 

 not being in search of the impossible, and that therefore the know- 

 ledge and the certainty that the microscope had indeed been invented 

 had been of such help to me that perchance without that I should 

 not have discovered it. To this I reply that the help rendered me 

 by the knowledge did indeed stimulate me to apply myself to the 

 notion, and it may be that without this I should never have thought 

 of it. Beyond this I do not believe that knowledge to have facili- 

 tated the invention. But, after all, the solution of a problem, 

 thought out and defined, is a work of some skill, and we are not 

 certain that the Dutchman, the first inventor of the telescope, was 

 not a simple maker of ordinary lenses, who, casually arranging 

 glasses of various sorts, happened to look through the combination 

 of a convex and a concave one placed at various distances from the 

 eye and in this way observed the effect that followed thereon. But 

 I, moved by the knowledge given, discovered it by a process of 

 reasoning." (II snggiatore, Rome, 1623.) 



(15) Galileo's account of the path of light in the bilenticular sys- 

 tem is unsatisfactoiy, but was improved by Kepler in his Dioptrice 

 (Cologne, 1611), who at the same time suggested that form of 

 microscope consisting of two convex lenses which has developed as 

 our modern instrument. 



