466 Proceedings of the Royal Institution, 



Steam-Engine, and on the means of obtaining motive power from 

 the Gases, were given in the Lecture-room by Mr. Millington, 



In the Library were specimens of an Ichneumon, presented to 

 the Museum by Mr. Barclay ; and of the Horns of the Klippsprin- 

 ger Antelope, presented by Mr. Colebrooke. Literary works as 

 usual. 



Friday, June Ibtk, 



Mr. Faraday gave an account of the progress and present state 

 of the Thames Tunnel. It was illustrated by many fine drawings 

 from the office of Mr. Brunei; by such parts of the apparatus used 

 as was sufficiently portable ; by models, and by specimens of the 

 earth raised from different parts, and of the articles which had at 

 various times made their way through from the river into the 

 shield. After describing generally the sinking of the brick tower, 

 which constitutes the larger part of the present shaft ; the particular 

 means employed for advancing the tunnel horizontally, i. e. the 

 construction, nature, and use of the shield, were dwelt upon and 

 explained. That being done, some of the extraordinary circum- 

 stances against v/liich the shield had to contend, and over which it 

 successfully prevailed, were described ; as, for instance, the occur- 

 rence of a pot-hole of gravel, the nature of the moistened silt, the 

 rapid entrance of water, and the runs of earth. A particular 

 history of the late entrance of the water in such manner as to fill 

 the tunnel was then given, with the modes adopted in examining 

 the hole that had been formed, by means of the diving-bell ; in 

 filling it with bags of clay, and covering it with grouting ; and the 

 description was continued to the formation of the second hole, the 

 satisfactory results that were obtained upon the examination of that 

 and the former, the means adopted for the purpose of stopping it, 

 and the progress made in proving them. The subject was con- 

 cluded "by general remarks upon the abundant reason there was, 

 from the efficacy of the means, from the good ground in advance, 

 and from the. known and tried talents of Mr. Brunei, to expect a 

 successful result to jhiB. bold and arduous undertaking. 



Ill the Library were two Guanches, from Teneriffe, belonging 

 to Mr. Brettell ; a complete set of specimens of Rock Salt, pre- 

 sented to the Museum by Mr. Leigh ; new Transactions of various 

 Societies, and new literary works. 



The Meetings were then adjourned to the next season. 



