344 [September. 



Salem, Young Men's Mercantile Library Association at Cin- 

 cinnati, and the Troy Rensselaer Institute; from Dr. Rusch- 

 enberger; from Archibald Campbell, of the N. W. Boundary 

 Survey ; from Hon. Charles Sumner ; from the Editors of the 

 American Journal of Arts and Sciences ; from the Franklin 

 Institute ; and from the publishers of the Medical News. A 

 donation to the cabinet of "Indian Relics," by Dr. Joseph 

 Leidy. 



The death of Sir Michael Faraday, a member of this So- 

 ciety, was announced as having occurred on the 25th of Au- 

 gust last, in the seventy-ninth year of his age. 



Mr. P. W. Sheafer presented the following communication, 

 — an account of the effects of lightning in the underground 

 workings of the Short Mountain Company's coal mines in 

 Dauphin County, Pennsylvania, by Gilliard Dock. 



WicoNisco, Pa., Sept. 5, 1867. 

 P. W. Sheafer, Esq. 



Dear Sir : On the 20th of June last, during a thunderstorm, 

 the lightning struck the iron rails leading into the water-level drift, 

 at Short Mountain Colliery, and passed into the mines. 



A driver who was coming out with a train of coal-cars, distant 

 about 450 yards from the mouth of the "drift," saw a flash of light 

 at a point near him, where the continuity of the rails was broken; 

 there was also a loud report, described as resembling the noise of a 

 large shooting-cracker. 



At a distance of 900 yards from drift mouth, there is a timber 

 " chute," leading down to a counter-gangway, 102 yards below water- 

 level; this "chute" also ventilates the lower part of the mines, and on 

 that day there was a strong current of air passing down. 



There are no iron rails, nor any other metallic bodies in this 

 ''chute." 



The next appearance of the electric current was at the foot of this 

 "chute," where it was seen to strike on the iron rails laid in this 

 gangway. There was a very distinct flash and report when the light- 

 ning touched this rail; the noise was so loud as to frighten two 

 mules standing near by, and they ran away from their driver. 



It then followed the rails westward, still travelling in the direction 

 of the ventilating current. 



At a point 250 yards west of the "chute" there is a "turnout," 



