xviii Mr. Pickering’s Eulogy on 
the house; and this correction he applied to all his observa- 
tions. 
I have given these particulars for the purpose of showing, with how 
much care he proceeded in his investigations, and how cautious we 
should always be, in admitting unqualified statements on questions of 
science which require delicate and accurate experiments, and thus 
hastily proceeding to account for a supposed phenomenon, before we 
have ascertained the fact of its existence. 
But, in order to give a more complete view of the labor of con- 
ducting such a course of experiments, I ought also to state, that 
during those four years Dr. Bowditch made no less than five 
thousand one hundred and twenty-five observations; the result of 
all which was, that the needle had not then experienced any change 
of variation in this part of the country, but continued to approach 
the true meridian with nearly the same velocity as at the time of the 
earliest observations on record; that is, nearly about 1’ 19” a year.* 
This interesting and valuable paper was followed by one relating 
to a subject, which can hardly be made intelligible without a more 
minute explanation than can be given in this place, — the Motion of 
a Pendulum suspended from two Points. The experiment was first 
suggested and made by Professor Dean of Vermont, to illustrate 
the apparent motion of the earth as viewed from the moon. Dr. 
Bowditch was much interested in this experiment; and he under- 
took to examine the theory of the motions of a pendulum suspended 
in that manner. The singularly curious and interesting results of 
his investigation are contained in the paper here referred to.t 
His next communication to the Academy was on an important 
mistake which existed for half a century in the Solar Tables of 
Mayer, La Lande, and Zach. And on this subject it should be 
* Mem. Amer. Acad. Vol. III. p. 337. See Note G, at the end. 
+ Mem. Amer. Acad. Vol. III. p. 241. 
