GARDNER.] GEOGRAPHY ELEVATION OF DATUM-PCINTS. 



635 



Elevation of Buffalo, Cleveland directrix, and mean surface of Lalce Erie — Continued. 





Feet 



Various datam-planes. 



Elevation in feet 

 above mean sur- 

 face of Atlantic 

 Ocean. 



Tliird determination— ConiinneA. 

 Clevelanfl, L. S. depot track, by profile of L. S. & M. 



0.70 



Above Buffalo depot track. 





S.R.II. 



583 77 



Cleveland, L. S. K. K. depot tract, by city-engineer re- 

 port. ' 



8.5 



Above city-directrix 







575 27 









572 67 



Fourth determination. 



.•!c0. 00 

 30.25 



Above M. T. Baltimore . . . 





Pa.E.R., westof Harrisbnrffb, byprofile of N.C.E.R. 

 Harrisburw'b, Market street depot track 



Below junction of !N. C 





i)o . 1 





319. 75 



Surface of L.-ike Erie, (year not given,) by P. & E. E. E. 



251. 00 



Above Harrisburgh 







570. 75 



Fifth determination. 



606. 80 

 582. 20 



14.5 



8.5 



23.00 



Above M. T. ITew York . . 





Surface of Lake Erie at Dunkirk, by profile supposed 

 to be from construction-ievels. 



(The present chief engineer reports that the line h.is 

 been rerun, and that the old and new lines differ 

 over 20 feet in some places. After examining the 

 old and new levels, he gives preference to the old, 

 but considers both incorrect.) 



Cleveland, L. S. depot, by L. S. & M. S. E. E 



do 





Below Dunkirk 





Below Cleveland depot 





Cleveland directrix 



Below Dunkirk 





Do 





583. 80 









581. 20 



(This result is rejected iu making up the means, be- 

 cause the levels are condemned by the chief engi- 



Sixth determination. 

 Surface of Lake Ontario by G. T. E. "W. of Canada 







240. 27 



Surface of water in Detroit Eiver opposite Detroit, 



by G-. W. E. \Y. of Canada. 

 Surface of Lake Erie by State geological survey report. 

 Surface of Lake Erie.'. 



328. 40 

 3.00 



Above mean surface of 



Lake Ontario. 

 Below river at Detroit 









571. 67 



Final results. 



Lake Erie : 



First determination 





Mean surface 



573. 08 







do 



572. 037 







do 



572. 670 







do 



570. 750 







do 



[581. 20) 

 571. 67 







do 



Adopted result. 







573. 08 



1844 to 18.57. 

 Differences of other results from the one adopted. 



- 1.04 



- 0.41 



- 2.33 



- 1.41 













Fourth determination differs 







Sixth determination differs 



do 





(The first determination is adopted, because it is the 

 final result of many years' leveling on the Erie Canal, 

 connected with the mean of thirteen years' observa- 

 tions on the surface of the lake.) 



Cleveland directrix : 





.575. fiS 









574. 637 



Third determination 







575. 270 



