Rail Road Tunnel. ■ 73 



leghany, Laurel and Chesnut ridges of mountains to their present 

 height. At the Connemaugh salines, only one bed of coal is found 

 above the surface of the river, the other two seen at the works be- 

 low, are yet probably beneath, owing to the lesser elevation of the 

 'hills at this spot. At Johnstown, four miles from the foot of the Al- 

 leghany mountain, the canal ceases, and its place is supplied by a 

 rail road across this mountain range, over to the waters of the Ju- 

 niata on the south side of the ridge. A narrow, but lofty spur of 

 the mountain opposes the further progr^s of the road at this spot, 

 to overcome which a passage has been made by tunneling through 

 its rocky sides. The length of this tunnel is eight hundred and sev- 

 enty seven feet. It is twenty four feet in width and twenty feet in 

 height. The rocks, penetrated by the tunnel are all of the secon- 

 dary class, composed of sandstone of various qualities ; some con- 

 taining a large proportion of mica, and others very compact, hard, 

 and sparry, approaching the transition class, which is the prevailing 

 rock in the Juniata hills on the south side. There are slate rocks 

 of different textures, from loose slaty clay to compact ; brown shale 

 or clayey marl, quite hard when first removed from its bed, but de- 

 composing and crumbling into earth after exposure to the air and 

 rains. On the north side, is a thin stratum of coal from six to eight 

 inches in thickness, extending south for two hundred feet. It hes 

 on the floor of the tunnel, and rises five feet in that distance, when i^ 

 runs out or is exhausted. " In the slate, are found numerous im- 

 pressions of leaves ; the trunks of large trees, and the scales of very 

 large fishes, as broad as the thumb nail." This statement I have 

 from Mr, Appleton, one of the contractors for excavating the tun- 

 nel. It is possible that the supposed fish impressions are made by 

 the scaly bark of the palm tree. The trunks and branches of va- 

 rious species of this family, being found in all the western coal strata. 

 The impression being in slate, is in favor of their being Ichthyolites. 

 The greater part of the fossils found in this region are in bituminous 

 slate or in deposits connected with the coal series. A fine collection 

 of these interesting fossils was made by Mr. Appleton, for his friend, 

 the Rev. C. Elliot, and carefully packed in a cask and forwarded for 

 him ; but by the carelessness and wanton neglect of the agent of a 

 warehouse on the route, they were all destroyed and lost, so that 

 when Mr. Elliot called for them in the spring, nothing could be found 

 but the staves of the cask. He had kindly promised to share the 

 collection with me ; and from these ancient, rare, and authentic re- 

 VoL. XXIX.— No. 1. 10 



