7o Royal Institution of Great Britain. 



May 8th. — A complete and practical illustration of the nature and 

 efficacy of the well known block machinery invented by Mr. Brunei, 

 and erected at Portsmoutli Dock Yard, was given by Mr. Faraday ; 

 the operations were all shown by means of the working models in 

 possession of the Navy Board, which carried the process through upon 

 a two sheaved block, four inches in length. 



Some very large and peculiar crystals of sulphate of copper and 

 carbonate of soda, presented to the laboratory, were placed with the 

 presents in the library. 



May 15. — A full and operative illustration of the principles and 

 practice ofwood-engraving was given by Mr. Mason. It was illustrated 

 by a numerous and well selected set of blocks, ancient and modern, 

 foreio'n and English, and also by wood-cut impressions of all ages, 

 sizes, style, and value. 



Amongst other things in the library was a very complete set of the 

 veoeto-alkalies, with other proximate vegetable principles ; placed 

 there by Mr. Morson. 



May 22nd. — The evening's demonstrations related to the acous- 

 tical fi<^ures assumed by vibratory surfaces, and rendered evident 

 by the superposition of heavy particles. It was given by Mr. 

 Faraday for Mr. Wheatstone. Since the discovery of these forms 

 by Chladni, they have rapidly risen into more and more importance, 

 because of the sensible indications which they afford of those inter- 

 nal powers of solid matter which relate to cohesion, elasticity, &c. : 

 the late researches by Savart show that they are a test far sur- 

 passing even polarized light in some respects, when applied to this 

 species of investigation. Mr. Faraday's object was to commence with 

 the earliest and simplest phaenomena; to trace them, as Chladni the 

 discoverer had traced them, to the more complicated effect ; to con- 

 nect them with the researches of Savart upon communicated and 

 reciprocated vibrations, which were shown to be equally competent 

 to produce these forms : — and then to give the general expression of 

 the laws governing these phaenomena. Upon the latter point some new 

 matter was promised on a future occasion. The whole was illus- 

 trated by extensive series of diagrams and experiments. 



A magnificent specimen of crystallized glass presented by Mr. 

 Cookson was exhibited in the library. 



May 29tli. — The discourse this evening was rather literary than 

 scientific, and was on the fictile vases of the ancients, by Mr. Singer 

 the librarian. An extensive series of large and small vases was 

 upon the table, and drawings of others placed up for illustration. 



June 5th. — t)r. Clarke, who a few years since visited and ascended 

 Mont Blanc, and made a considerable botanical and mineralogical 

 collection in its neighbourhood, placed his collection upon the table, 

 caused numerous drawings to be suspended for reference, and un- 

 dertook to describe to his fellow-members the ascent and descent 

 of Mont Blanc, and the natural history of the mountain. He had 

 not time to complete more than half his object, and the communi- 

 cation will be resumed on a future evening. 



June 12th. — On this evening Mr. Faraday gave an account of the 



experi- 



