Barker.] 114: \,, v |.-,, 



Railroad ; Mr. Henry Keep and Mr. M. L. Sykes, of the Chicago and North- 

 western Railroad ; Mr. Sidney Dillon and Mr. Jay Gould, of the Onion 

 Pacific Railroad ; Mr. William IT. Fargo, of the American Express Com- 

 pany : Mr. Frederic Lovejoy, of Adams' Express Company, and the Super- 

 intendent of the Union Pacific Express Company. The cordial appre- 

 ciation by these gentlemen of the fact that the work in which we were en- 

 gaged was one of a purely scientific character, and as such was one to which 

 every reasonable facility should be furnished, was as gratifying to us as it 

 was honorable to them. I should fail to do exact justice were I to omit 

 mention of the service rendered us by Mr. J. J. Dicke}', the Superintendent 

 of the Union Pacific Telegraph; Mr. E. Dickenson, Superintendent of the 

 Laramie Division; Mr. R. M. Gaihraith, Superintendent of the Repair Shops 

 at Rawlins ; Major Thornhurgh, Commanding Officer at Fort Fred Steele, 

 with Capt. Bisbee and Surgeon De Witt, his associates in the service ; 

 Mr. Lawrence Hayes, of the Railroad Hotel, and to Mr. J. B. Silvis, of 

 the photographic car. " Of the citizens of Rawlins," says Dr. Draper, " it 

 is only necessary to say that we never even put the lock on the door of the 

 observatory, and not a thing was disturbed or misplaced during our ten 

 days of residence, though we had many visitors." 



The agreeable party, the pleasant surroundings, the charming weather, 

 the kindness of friends, and above all, the capital success of the observa- 

 tions, make the Draper Eclipse Expedition an exceedingly pleasant 

 memory to us all. 



Xotes on a series of Analyses of the Dolomitic Limestone Rocks of Cumber- 

 land County, Pa., made by Messrs. Hartshorne and Hartranft in the 

 Laboratory of the Second Geological Survey of Pennsylvania. By J. P. 

 Lesley, State Geologist. 



{Read before the American Philosophical Society, October \%th, 1878.) 



At a meeting of the American Philosophical Society, Dec. 20, 1877, I 

 described the progress of an elaborate investigation which I had instituted 

 for the purpose of determining whether or not any fixed or rational order 

 of deposition could be observed in our Lower Silurian, or Siluro-Cambrian 

 Magnesian Formation (No. II). 



I selected a fine exposure made by the rock cut of the Northern Central 

 Railroad, on the west bank of the Susquehanna river, opposite Harrisburg, 

 where a consecutive series of the beds, all conformable and all dipping 

 regularly about 30° to the southward, afforded a good opportunity for col- 

 lecting two sets of specimens for analysis, one at the bottom and the other 

 at the top of the cut ; and great care was taken to survey the cut, mark the 

 beds (from 1 to 11")) and range the specimens in two parallel series ; so 



