Scientific Memoranda. 567 



Royal Geographical Society of London. — A communication was 

 made and received with great satisfaction, that Dr. Richardson, 

 the able and intrepid companion of Sir John FrankHn in his 

 polar expeditions, had volunteered his services to his Majesty's 

 government to conduct an expedition from the Hudson's Bay 

 G)mpany's settlements to the Northern Ocean, in search of 

 Capt. Ross ; and that sanguine hopes were entertained that this 

 offer would be accepted, and a small expedition fitted out ac- 

 cordingly. 



Royal Institution of London. — Professor Ritchie exhibited the- 

 arrangement he had made for obtaining the spark from the 

 magnet, and exploding' gases by its means. The experiment 

 was very successfully performed several times. Mr. Farraday 

 showed the arrangement he had adopted for obtaining the spark, 

 which he rendered beautifully visible. The magnet he used 

 was the natural loadstone belonging to Professor Daniell. 



On the Crispations of Fluids lying on vibrating surfaces. — 

 Since the reading of his paper, in 1831, before the Royal Soci- 

 ety, on certain forms assumed by particles on vibrating surfaces, 

 Mr. Farraday pursued the investigation, and extended the prin- 

 ciples in explanation of the curious configurations observed by 

 Orsted and Wheatstone, on the surfaces of fluids on vibrating 

 plates. By gradual experiment he connected these minute ap- 

 pearances with one form of stationary undulations, and showed 

 that the direct motion of the plate to and fro was with respect 

 to the fluid converted into a reciprocating lateral motion ; the 

 fluid dividing, as it were, into quantities, which, on rising, formed 

 heaps, and on falling gave origin to a similar set of interposed 

 heaps, which again passed back into the first set, and so on con- 

 tinually. Various forms of vibrations v^'ere shown ; thus, if a 

 cylinder just touching the surface of the water be made to vibrate 

 up and down rapidly, radii form all around it to a great extent, 

 as if elevation and depressed lines were passing directly out- 

 wards. Mr. Farraday then considered the possibility of similar 

 effects taking place in elastic media surrounding the vibrating 

 plate, in which case the elasticity allowed of what could only 

 take place in dense inelastic media by a suddenly terminated 



