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Proceedings of the Royal Institution of Great Britain. 



FRIDAY EVENING MEETINGS. 



Jan. 21st. THE meetings for the season commenced this evening, 

 and will be continued every Friday, except those of Passion and 

 Easter weeks, until the 10th of June. The subject in the lecture- 

 room, upon the present occasion, was given by Mr. Faraday, being, 

 in fact, the developement and illustration of that peculiar class of 

 optical deceptions which forms the object of the first article in the 

 present Journal, p. 205. The effects were shown by large wheels 

 cut out of pasteboard : those produced, by casting the shadows of 

 the moving wheels upon a screen, were exceedingly well exhibited 

 by means of the cone of rays from a magic- lantern. The appear- 

 ances exhibited by reflection were also well shown ; and, as some 

 effects beyond those mentioned in the paper had been observed, 

 and were explained, Mr. Faraday will add a note of them at the end 

 of these proceedings. 



In the library, Mr. Cuthbert showed the power of his beautiful 

 microscope, by exhibiting some wheel animalculae ; and Mr. Varley 

 also exhibited more of these animals, by means of excellent micro- 

 scopes in his possession ; the object was to give the members an 

 opportunity of seeing the appearance of this curious creature, that 

 they might the better understand the references made to it by 

 Mr. Faraday, in pursuance of his subject. 



Numerous presents of specimens of natural history, books, en- 

 gravings, &c. &c. were laid upon the library-table. Mr. Pepys 

 brought to the meeting a very beautiful piece of American glass 

 casting ; it was a small plate, the upper surface smooth, but the 

 under surface covered by a beautiful design of scroll-work, &c. in 

 very high relief, so that, as the plate stood upon a table, the reflec- 

 tion of light from it was of the most brilliant and metallic kind. The 

 plate had been cast, the wheel had never touched it, yet the surface 

 VOL, I. FEB. 1831, Z 



