874 oS. T. Gardner—Hypsometric Survey of the Territories. 
above the sea, connected with it by three spirit-level lines, one 
running to the Pacific and two to the Atlantic 
he second station, Cafion City on the Arkansas River, at 
about 6000 feet high, is 90 miles south of Denver. The obser- 
vations of the classes to which these stations belong, that is 
those between 5000 and 8000 feet, will almost all be taken 
within 60 miles of the base stations. 
The third station is Fairplay, in the South Park, 60 miles 
S.W. of Denver, and about 10,000 feet above the sea. 
The fourth is Mt. Lincoln, 10 miles from Fairplay. On the 
central position of this peak among its compeers that so ad- 
mirably fits it for a base of reference for all their heights. 
The vetrical circles of the “ gradienter,” with which this hae 
done, are small—four inches only in diameter; but they 
hed levels are 
g. 
The check observations are so arranged d that the system 
error can be easily determined, and it is hope oun 
will prove accurate enough to throw some light on the am the 
of refraction in these high altitudes. The comparison btedly 
barometric system with the trigonometric will undou 
