MEMOIRS 
OF THE 
AMERICAN ACADEMY. 
ET. 
An Account of the Magnetic Observations made at the Observatory 
of Harvard University, Cambridge. 
COMMUNICATED 
BY JOSEPH LOVERING, 
HOLLIS PROFESSOR OF MATHEMATICS AND NATURAL PHILOSOPHY. 
Tue plan and occasion of the magnetic observations which 
have been made at Cambridge, under the auspices of the Acad- 
emy, have been developed at length in a former communication. 
The observations which had been made previous to the date of 
that paper were then published. Since that time, a similar series, 
according to the same general system, has been sustained, at 
longer or shorter intervals, as circumstances permitted. The ob- 
servations on the Term-days were made under the superintend- 
ence of Mr. W. Cranch Bond, the Astronomical Observer of the 
College. Those observations are not included in the present 
publication. They have already been presented in manuscript to 
the Academy, and will, I trust, be soon published, and distributed 
among all who are interested in these researches, 
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