110 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Pig. 12. 



Our fig. 11 is copied from the original. It will thus bo seen that 

 our conjecture as to the early date (jxnte 1665) of tho construction, based 

 upon the absence of a field-lens, may possibly need qualification in the 

 face of tho publication (apparently the first of 

 this form of Microscope) in 1G86. 



From various references we have met with, 

 and notably from the paper ' Nvove inventioni 

 di tubi ottici ' (a contribution to the ' Accademia 

 Fisico-matematica,' of Home, in 1686, by — wo 

 believe — Ciampini, tbe then editor of the 

 ' Griornale de' Lettcrati,' of Eome) Campani's 

 Microscopes appear to have been well known 

 at that date, so well known, indeed, that any 

 resemblances to them in more recent models 

 were at onco noted. 



Attention may be called to the curious 

 mixture of scales in the drawing. The large 

 Microscope on the left is the same instrument 

 as is represented by the two small ones in tho 

 centre and on the right. The artist, it will be 

 seen, has introduced a diagram of an eye above 

 the large Microscope, a proceeding which, 

 although it looks very odd in such a picture, 

 had the useful effect of checking the scale and 

 preventing the instrument from being taken to 

 be of the same proportions as the men who 

 accompany it in the drawing. It will be re- 

 membered that it was the blunder of an artist 

 in substituting a man for an eye, that led to 

 the ludicrous misinterpretations of Schott's 

 fe Microscopes on which we commented in this 

 Journal, 1887, p. 148. 



In a more recent visit to Italy than that 

 referred to in our previous note on this subject, 

 we met with the very early form of Microscope shown in our fig. 12. 

 The body-tube is of cardboard covered with marbled paper, and slides 

 in the split ring-socket on the top of the tripod for focusing. A draw- 

 tube of cardboard carries an eye-piece with a field-lens — the lenses 

 mounted in wood cells. The instrument is in the " Museo di Fisica," 

 Florence where apparently nothing definite is known of its origin. We 

 are however able to assign the construction with considerable proba- 

 bility to Campani from the fact that at the " Conservatoire des Arts 

 et Metiers " Paris, there is a practically identical Microscope bearing 

 the inscription, "Giuseppe Campani in Eoma 1673." It is thus evident 

 that Campani constructed eye-pieces with, and also without field- 

 lenses. 



L., A. S.— Differential Screw Slow Motion— To Mr. Crisp. 



[Claim to have anticipated by sixteen or seventeen years Campbell's differential 

 screw fine-adjustment. Cf. this Journal, 1887, p. 324.] 



Engl. Mech., XLVI. (1887) p. 416. 

 Kousselet, C— On a small Portable Binocular Microscope and a Live-box. 

 [Microscope not figured. Live-box, infra, p. 112.] 



Journ. Quek. Micr. Club, III. (1887) pp. 175-7 (1 fig.). 



