126 Annals of the Philosophical Club 



completed. 1 The chief were : bad building materials, bad 

 foundations (sand and alluvial mud), and the impetuous 

 torrents, due to the proximity of mountains. He described 

 how these especially the second and third had been 

 overcome ; the former by constructing either vertical 

 cylinders of brick or blocks of the same material, perforated 

 with similar cylinders, which were allowed to settle down, 

 till they came to rest in the sand. In this way whole piers 

 and abutments of bridges were constructed. The latter 

 difficulty the large and rapid torrents was overcome by 

 carrying them either under or over the canals. 



Colonel Portlock, in reply to a question, gave some 

 account of the siege of Sebastopol, which, he said, presented 

 exceptional difficulties, because of the rocky nature of the 

 ground. Still, notwithstanding these, the progress by 

 blasting had been wonderful, and the final result was not 

 doubtful. 2 



Dr. Hooker exhibited some fine specimens of fossil leaves 

 of dicotyledons, apparently trees, brought by Captain 

 Beechey's expedition from Disco Island (Greenland). These 

 were peculiarly interesting as coming from a region within 

 the Arctic circle, now occupied by a very different vegetation. 

 They occurred in a shale, overlying thick beds of coal, and 

 probably belonged to the Tertiary era. 3 



Mr. Grove informed the Club that he had seen a medal 

 of the new metal aluminium, considerably larger than half a 

 crown. Its colour was good, its outline sharp, and its 



1 He had superintended that work in 1843-5 and 1848-54, being created 

 K.C.B. in the last-named year. 



"The siege of the southern side, on which the defences had been 

 hurriedly prepared by General Todleben, began late in September, 1854. 

 After the capture of the Malakoff and Redan on September 8th, 1855, that 

 side of the city was evacuated by the Russians. 



3 Since the above date, many specimens have been collected and brought 

 to Europe. Heer in Flora Fossilis Arctica, 1868-73, described 137 species. 

 These include many kinds of trees, thirty of them conifers ; also beeches, 

 oaks, and magnolias. He considered them to be Miocene in age. See 

 A. Geikie, Text Book oj Geology, page 1271. A similar flora (with iignite> 

 was found by Captain Feilden at Discovery Bay, Grinnel Land, lat. 81 45' 

 N., in 1876. Heer, Quart. Jour. Geol. Soc. 1878, page 66. 



