Carll. | 18 [May 4, 
Rail Road Junction ; at Red Bank ; at Parker’s ; at Oil City ; and at Corry. 
In 1875 the engineers in charge of the A. V. R. R. re-leveled its track from 
Kittanning up to South Oil City, but their work was based on the Kittan- 
ning bench-mark, the true elevation of which was in doubt. So that pre- 
vious to the commencement of these examinations and our adjustment of 
the levels, we had not been able to secure a single elevation along the A. 
V. R. R. on which it seemed safe to rely. 
As the shortest way out of these difficulties, and to establish some reliable 
base for the use of the survey, a re-leveling of the road, as far as might be 
necessary was resolved upon. Accordingly, early in February 1877, Mr. 
John H. Carll and Mr. Arthur Hale, provided with a superior rail road 
level and staff, proceeded to Pittsburgh to commence the work. 
Every facility was afforded by the Chief Engineer of the Railway, Mr. 
H. Blackstone, to whom our thanks are due for these courtesies, for the 
examination of profiles and note books, and all the data of use secured from 
the office of the Rail Road Company. 
Our levels were commenced at the Union Depot bench-mark and carried 
forward continuously to the old Kittanning bench-mark. A table compar- 
ing the results with a Railway profile, is appended. It shows a difference 
of only 22, of a foot between the Railway profile elevation of the Kittan- 
ning bench-mark and our own ; and establishes the height of this bench at 
809.94’ above mean surface of the Atlantic Ocean.* 
From Kittanning to South Oil City there is a rise of 299.20’ according to 
the Rail Road levels of 1875. But in a table of elevations furnished the 
Smithsonian Institution by the engineer of the road shortly after its com- 
pletion, the difference between the same points is given as 298’. The lev- 
els of 1875, consequently, make the elevation of South Oil City 1009’, the 
old levels 1008’. 
From W. Pennsylvania Junction our re-leveling was carried on up the 
Butler Branch Rail Road, to Great Belt City. Here connection was made 
with our line run along the oil belt by Messrs. Hatch and Hale in 1875 and 
by Messrs. Chance and Hale in 1876. This last named line was then 
adjusted tothe Pittsburgh datum, traced back to Parker’s depot and found 
to coincide there within 45 of a foot with the Allegheny Valley Rail Road, 
corrected elevation—thus showing a very reliable circuit from Allegheny 
Junction to Great Belt, from Great Belt to Parker’s and from Parker’s back 
to Allegheny Junction. So far the levels appear to be satisfactory. 
From Parker's to Oil City, the following check was kindly furnished by 
Mr. D. Jones Lucas, Resident Engineer of the Union Pipe Company. Mr. 
Lucas ran a line of levels across the country in 1875 from Parker’s depot to 
Oil City (Union Depot), and found the difference in elevation to be 118.9’. 
This added to our accepted elevation of Parker’s 889’, gives 1008’ as the 
proper height of Oil City (U. Dep.) which is 0.45’ lower than the South 
Oil City Depot: 
* As established by United States Coast Survey in New York Harbor. 
