H. A. Hazen—Projection of Lines of Equal Pressure. 3868 
TABLE II, 
Difference of Elevation. 
Month. Mt. Wash’g’n,| Pike’s Peak, |Dodge C., Ka.,| Pioche, Nev., |Boise C., Ida., 
N.H., & Port-|Col., & Dodge| & Leayenw’h,| & Visalia, & Umatilla, 
land, Me., 6 ys’|City, Ka ,4 ys’|} Ka.,4 years’ | Cal., 1 years’ |Oregon, 1 yrs’ 
observations. | observations. | observations. | observations. | observations. 
January 6264’ 11331’ 1665’ 5648’ 2301’ 
February 6268 11414 1670 5758 2302 
March 6284 11452 1725 5797 2398 
April 6242 11485 1718 5821 2485 
6232 11525 1734 5852 2495 
June 6233 11545 1734 5819 2540 
July 6225 11567 1752 5867 2522 
6215 11565 1752 5792 2530 
September 6236 11535 1756 5800 43 
6249 11426 1722 5722 2381 
November 6275 11382 1670 5702 2343 
6259 11326 1667 5637 2342 
Year 6256 11470 1716 5172 2424 
Mean of 12 mo’s 6248 11463 1714 5768 2424 
Mean 6252 11466 1715 5770 2424 
True diff. level 6240 
In column 2, Mt. Washington is in latitude 45° north, near 
the Atlantic coast and sixty miles west of Portland, which is 
46! above the sea. In column 3, Pike’s Peak is in the interior 
In latitude 39° north and 300 miles west of Dodge City, lel 
hear the Pacific coast and 870’ high. In column 6, Boise City 
'S In latitude 44° north and about 200 miles southeast from 
_ The most noticeable fact is that while the computed eleva- 
tions on the Atlantic coast gradually diminish from January 
Portland is within 12’ of the truth. In the west many of the 
elevations are in doubt. 
_ Table IIT gives approximate elevations of most of the sta- 
tions west of the Mississippi River. 
itis 58°-5. These temperatures reduced to sea level at the rate 
of 1° for each 300’ elevation are, 66°°7, 61°-9 and 66°°3 respec- 
tively, Again, we frequently find the temperatures ten to fif- 
