Variation of the Magnetic Needle. 69 
The variation observed by Doctor Williams at Rutland, 
in Vermont, leads to the same result. is observations at 
that place were 
1789 April 17 7° 3) W 
1810 May 19 6 4 
1811 Sept. 9 6 1 
Whence he concludes, that the magnetic variation at Rut- 
land, for twenty two years past, has been decreasing at the 
annual rate of 2’ 49’5. 
III. In May, 1819, the late Professor Fisher of Yale Col- 
lege, commenced a series of observations on the declination 
of the needle, which were continued, from time to time, un- 
til April, 1820. The instrument employed was a variation 
compass, which had been recently constructed by a skillful 
artist, and had all the appendages necessary for the nicest az- 
imuth and altitude observations. From Mr. Fisher’s notes, 
we collect the following results, being the means of a great 
number of trials at different hours of the day. 
Declination of the needle West. 
1819, May, . - - 4,.° 26° 
une, «<< - - - - 4. 28 
July, : . s 4, 25 
August, - - ~: - 4, 22 
September, - - - 4. 30 
] mber - - Se ee 
1820, January, ’ : 4, 25.5 
February, - - ace. Det 
March, - - - eg 
April, - - - a a Oe 
Mean, - . - - 4.° 25.'42 
Remark.—It appears from the foregoing observations, that 
the declination of the needle at New Haven, in the years 
1819 and 1820, was less than had been observed at either 
of the places mentioned in the first of the above articles. 
The least declination given by the Hon. Mr. De Witt, was 
in August 1818, and amounted to 5°. 45’, which is about 
1°, 20’ greater than the mean of the observations of Profes- 
sor Fisher. 
