0. T. Sherman—Magnetic Observations in Davis Strau. 49 
Art. VIII. — Magnetic Observations made in Davis Strott, in 
August and September, 1880, on board the Steamship Gulnare ; 
by O. T. SHERMAN. 
THE Steamship Gulnare was provided with a Lamont mag- 
netometer, made by Fauth & Co., and a Kew dipping needle, 
made by Cassella. Before the starting of the expedition, both 
instruments were set up in the private observatory of Mr. C. A.’ 
Schott, in Washington, and the observers had the great bene- 
fit of his advice. The methods of observation, the forms of 
record and reduction are recorded, in part, in Appendix No. 
16, Coast Survey Report, 1875, in part in the ‘ Admiralty 
Manual of Scientific Inquiry.” Frequently, however, it was 
found desirable to have recourse to the sextant to obtain the 
azimuth. 
The first observations we record were taken at St. John, 
a value 31° 30%. The variation chart, for 1880, published by 
the British Admiralty, shows the line of 31° ranning through the 
harbor. Our own value is 30° 40’. It is derived from five 
observations, four of which are absolutely independent. The 
extreme values differ among themselves by 6’-1 when reduced 
to the mean of 24 hours. This discrepancy I am at a loss to 
explain. No data are known which would refer it to local 
“canny The horizontal force observed was 3°3378, the dip 
° 45’: 
Lively, Disco Island, Greenland, formed our second station. 
This place had formerly been visited by Sontag in Sept., 1861, 
who band the dip 81° 51’ and the horizontal force 1°762, but 
who records no declination. It was again visited by the Alert 
and Discovery in 1875; the record then made the declination 
67° 12’-8-68° 45’, dip 81° 56’-81° 43’°7 and _ horizontal force 
1770-1'805. Total force, 12°514-12°578. The remark is added 
that the observations showed evidence of considerable local at- 
traction. Our record is one of disturbance only. On August 
llth, the declination observed by the magnetometer varied 
from N, 46° 97 W., at 11" 13" a. M., to N. 49° 15/3 W., at 4* 
32" Pp. M. On August 18th, at the same spot, but with an 
-4Zimuth compass, the declination varied from N. 67° 54-1 W., 
at 7 a. M., to N. 68° 52/4 W. at 3 Pp. M. Our needle was 
consequently deflected over twenty degrees by the magnetic 
storm of August 11th. On several successive days also, it was 
Am. Jour. a Sertzes, Vou. XXII, No. 127.—Jury, 1881. - 
