534 PROCEEDINGS OF THE SOCIETY. 



the eminent Italian physician, had referred to the magnifying power of 

 lenses in a vague manner in his ' Homocentrica,' published in Venice in 

 1538 ; but this reference did not jioint to practical knowledge, Giovanni 

 Baptista Porta had also been credited with the invention ; but later writers, 

 including Poggendorff, were doubtful if such was the fact. Libri was 

 inclined to credit Galileo with the authorship — at least, of the combinations 

 forming telescopes and Microscopes ; but, on the other hand, it was certain 

 that telescopes were known in Holland before Galileo's construction of these 

 instruments. The evidence which he had come across lately conclusively 

 showed that magnifying glasses were used at least as early as 1513-1520, 

 for in the celebrated portrait of Leo X. by Raphael the Pope is shown 

 holding one in his hand. This picture was painted between 1513 and 

 1520, as the Pope was elected in 1513, and Raphael died in 1520. Ho had 

 brought to the meeting a volume which had been lent for the purpose 

 by Mr. Quaritch, and which contained an engraving of Rajihael's portrait 

 of Leo X., so that the Fellows would be able to inspect it after the 

 meeting. 



During a recent visit to Florence he also paid some attention to the 

 Microscopes which had been attributed to Galileo. It was, of course, rather 

 difficult to say in such matters what was really authentic and what was 

 not ; but when these instruments were shown at the Loan Collection at 

 South Kensington, there were suggestions made that they had been prejjared 

 for that exhibition, though he was assured by Prof. Meucci that they could 

 be identified certainly since 1670, if not earlier. He could not, however, 

 help noting that all the early telescojies made in 1660, or about that 

 time, had cardboard tubes, and wood or horn cells for the lenses, whereas 

 these Microscopes were made with substantial brass body-tubes with strong 

 and well-made screw threads and firm tripod support. He could only say, 

 therefore, that if the Microscope makers had arrived at that stage of 

 perfection in Galileo's time, they had reached a point not attained by his 

 successors until many years afterwards. 



Mr. Mayall, in reply to an inc^uiry as to the supposed lens from Nineveh, 

 said he could not add to what he had already stated in the Cantor Lectures, 

 viz. that he did not find this so-called lens sufficiently clear to be used for 

 magnifying purposes. It was made of rock crystal, and he thought that 

 whoever intended to use it as a lens would have selected a piece without 

 the veins across, which so marred it for that purpose, though, regarding it 

 as an ornament, they rather added to its beauty. He thought Sir David 

 Brewster had been rather hasty in coming to a conclusion about it. There 

 had been also two pieces of glass found which had been taken for lenses, 

 being plano-convex. One it was not possible to see through, the other was 

 partly polished and might have been used as a burning-glass ; but he had 

 spoken to many authorities about them, amongst others to Mr. Madan, 

 and they seemed of opinion that they w^ere intended to be used as orna- 

 ments for the person, possibly for the helmet, or for the shoulder of the 

 tunic. 



Mr. J. Mayall, jun., also described a Microscope which had come from 

 Japan. It was made after one of the old upright tripod models, and had 

 a ring of inlaid silver ornamentation at both top and bottom, which was 

 made with characteristic skill ; but the person who had produced the 

 instrument, though he had provided a place for the objective, had omitted 

 to make any provision for the eye-piece. 



