Curious and manifold as are the trees associated with the great names
of their planters, or those who have sojourned in their shade, the
Tree which, by the falling of its fruit, suggested to Newton the idea
of Gravity, is of paramount interest. It appears that, in the autumn
of 1665, Newton left his college at Cambridge for his paternal home
at Woolsthorpe. “When sitting alone in the garden,” says Sir David
Brewster, “and speculating on the power of gravity, it occurred to him,
that as the same power by which the apple fell to the ground was not
sensibly diminished at the greatest distance from the centre of the
earth to which we can reach, neither at the summits of the loftiest
spires, nor on the tops of the highest mountains, it might extend to
the moon and retain her in her orbit, in the same manner as it bends
into a curve a stone or a cannon-ball when projected in a straight line
from the surface of the earth.”--_Life of Newton_, vol. i. p. 26. Sir
David Brewster notes, that neither Pemberton nor Whiston, who received
from Newton himself his first ideas of gravity, records this story of
the falling apple. It was mentioned, however, to Voltaire by Catherine
Barton, Newton’s niece; and to Mr. Green by Martin Folkes, President
of the Royal Society. Sir David Brewster saw the reputed apple-tree in
1814, and brought away a portion of one of its roots. The tree was so
much decayed that it was cut down in 1820, and the wood of it carefully
preserved by Mr. Turnor, of Stoke Rocheford.
De Morgan (in _Notes and Queries_, 2d series, No. 139, p. 169)
questions whether the fruit was an apple, and maintains that the
anecdote rests upon very slight authority; more especially as
the idea had for many years been floating before the minds of
physical inquirers; although Newton cleared away the confusions and
difficulties which prevented very able men from proceeding beyond
conjecture, and by this means established _universal_ gravitation.