Mount* St. Elias and Orizaba. — Lindenkohl. 215 
which gives b} T reduction 139° 46' 34.9" for the new station. 
The difference between the two determinations amounts, there- 
fore, only to thirteen seconds of arc. 
Triangulation. 
While Mr. Turner was engaged upon the astronomical 
work, Mr. McGrath measured a base of 6,831 meters (or 
about four miles) on the western shore of Yakutat bay, which 
he connected by a system of triangles with the astronomical 
station lying to the eastward, and also with Mt. St. Elias, 
about 47 miles distant to the northwest. The angle which is 
subtended by this triangulation at Mt. St. Elias is about 20 c , 
whilst the corresponding angle of Prof. Russell's work is only 
5° 23' 38" ; hence far more certainty is attached to the po- 
sition of Mt. St. Elias as derived from the observations of 
Messrs. McGrath and Turner. 
Besides the horizontal angles, vertical angles were meas- 
ured at each of the five occupied stations shown by the 
sketch. A greater weight was allowed to the zenith distances 
measured at the astronomical station, for the reason that a 
better instrument had been employed and that they extended 
over a longer period of time than the rest. The coefficient of 
refraction was obtained by reciprocal observation between 
this station and Mt. Hoorts, which has an elevation of 
2,076.5 feet and was found to be =0.083. 
The following series gives the means of the daily measure- 
ments of zenith distances of Mt. St. Elias taken from the as- 
tronomical station, each day's result being the mean of three 
sets of six repetitions each, the observations being made near 
noon. 
ZENITH DISTANCE OF MOUNT ST. ELIAS. 
June 11, 1892 87° 20' 50. 3' 
June 18, 1892 87 20 64.2 
June 27, 1892 87 20 51.8 
June 28, 1892 87 20 51.3 
July 9,1892 87 20 57.1 
July 10, 1892 87 20 49.8 
July 11, 1892 87 20 44.8 
July 13, 1892 87 20 40.6 
July 23, 1892 87 20 59.8 
July 29, 1892 87 20 36.1 
Aug. 1,1892 87 20 53.0 
Aug. 11, 1892 87 20 52.0 
Aug. 17, 1892 87 20 50.8 
Aug. 18, 1892 87 20 41.2 
Mean of 14 days s7 :!(> 50.2 + 1 
