142 Annals of the Philosophical Club 



on Etna. 1 There he had seen several compact lava streams 

 inclined at angles of from 20 to 40 ; that of 1688, which 

 is 5 feet thick, being as compact as ' Scotch trap.' In some 

 places it lay at an angle of 48, but its thickness here was 

 only 2\ feet. At one part of the mountain horizontal 

 lava beds rested on others which were highly inclined ; 

 thus indicating two centres of eruption, as it was at Teneriffe. 

 Nine-tenths of the fossils, collected from sedimentary beds 

 under Etna, belonged to existing species; so the volcano 

 had been built up in later Tertiary times. 2 



Professor Tyndall described his examination of the veined 

 structure in Alpine glaciers, to compare it with the slaty 

 cleavage of rocks. He had found the former cutting the 

 stratification of the snow at all angles up to 90. 



Dr. Falconer recurred to the excavations in the Devon 

 caves. The one carried inwards in a horizontal direction 

 above the stalagmite floor of the cavern had come upon 

 reindeer antlers in good preservation. About 2| feet 

 vertically below them, after breaking through this floor, 

 several specimens of what were known to antiquarians as 

 flint knives were found in good preservation. Then came 

 a ' bed of ochry loam ' about n feet thick, and then a 

 gravel, flint knives being found in both, and in the loam 

 bones of rhinoceros and hyaena belonging to the Glacial 

 Period. 



Mr. Wheatstone then exhibited some specimens of paper, 

 pierced for transmitting messages by a form of printing- 

 telegraph which he had invented. It could produce about 

 320 symbols or letters a minute. 



At the io6th meeting (Nov. 25th) General Portlock gave 

 an account of the trials of Armstrong's guns at Shoeburyness. 

 One, with a nine-pounder bore, but a rifled barrel, had thrown 

 an oblong 18 pounds shot, with an error of only 20 feet in 

 7000 yards. A 1 2-pound shot from a 6-pounder gun had 



1 Op. cit. vol. ii. pages 303-311. 



2 See Principles of Geology, vol. ii. page 6 (ed. n) for a more precise 

 statement, and chapter xxvi. for a general discussion of the structure 

 of Etna and its two eruptive centres. 



