ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



805 



the draughtsman, knowing possibly nothing of the purposes of the instru- 

 ments, instead of drawing an eye directed upon them, drew full-length 

 figures, whence by comparison the Microscopes appear of enormous size. 

 This explanation was suggested to us by certain figures of Microscopes in 

 Traber's ' Nervus opticus,' published in 1690, which we reproduced in 

 snjiport of our view of the matter. We have since met witli the first 

 edition of Traber's work, published in 1675, in which the same figures 

 were given. On comparing Traber's descriptions with those given by 

 Schott we are strongly confirmed in our opinion that the former was refer- 

 ring to the same Microscopes as those described by the latter. 



In support of our explanation we remark that our fig. 13 from Schott's 

 ' Magia IJuiversalis ' does not correspond with his own description of it (loc. 

 cit., p. 535), for he states that the Microscope is " super tripedale fulcrum," 

 though the drawing shows a cylindrical tube-support without any visible 

 means of illuminating the objects, and such as, in our opinion, was never 

 actually constructed. Whereas Traber's figure (our fig. 16) answers fairly to 

 Schott's description, the open tripod sujjport being a practical form that clearly 

 forms a link in the evolution of the mechanical designs of Microscopes. 



We omitted to note that Schott assigns the construction of the instru- 

 ment to Eustachio Divini thus: — " Huius modi microscopia excellentissima 

 facit Eomae Eustachius Divini . . . ." (loc. cit.). 



In further confirmation we remark that in another drawing given by 

 Schott four fig. 212) a candle and a lens are shown, and by comparison with 

 the full-length figure of a man kneeling and viewing the candle through 

 the lens the latter might be supposed 3-4 feet in diameter, quite beyond 

 the possibility of manufacture at that date. Schott states that from 

 Kircher's ' Ars magna lucis et umbrae' (1646) he found the lens was 



Fig. 212. 



FiH. 213. 



designed by Descartes to have hyperbolic surfaces. On reference to 

 Kircher's text we find Descartes and the hyperbolic surfaces mentioned, 

 thus identifying the instrument, l)ut the figure illustrating the text again 

 shows an eye only directed to the lens (vide fig. 213 reproduced from 

 Kircher), whence by comparison the lens appears to be only 4-5 in. in 

 diameter, a size that may have been reached at that date. In reproducing 

 Kircher's woodcut Schott's draughtsman is thus clearly proved to have 

 substituted a full-length figure of a man for the representation of the eye 

 only of the original ; the probability of his having done so likewise with 

 other drawings is hence easy to understand and our conjecture is thus 

 shown to have been the true expLmation. 



Another ludicrous feature may also be noted, viz. : — that in Kircher's 

 figure the eye is viewing an insect through the lens, which Schott's draughts- 

 man apparently mistook for a candle-flame, and hence siibstituted the latter ! 



