Thomas Godfrey Got a Valuable Idea by
Noting the Reflection of the Sun
from a Pail of Water.
Thomas Godfrey was probably the first self-made man in America. Born in
1704, he died in 1749. He was a glazier by trade, but he had naturally an
interest in mathematics, and he learned Latin in order that he might read
certain scientific treatises.
His reputation rests on an improvement which he made in the quadrant of
John Davies. What Godfrey really did was to invent the sextant. John
Hadley also invented a sextant, evidently carrying out a suggestion of
Newton's which was found in Sir Isaac's original draft among Hadley's
papers after his death. Godfrey antedated Hadley by about one year, but
for a long time his claims were not recognized, and Hadley received all
the credit.
How the humble glazier received his first inspiration to design the
instrument of so great use to mariners is an interesting story. One day,
while replacing a pane of glass in a window of a house on the north side
of Arch Street, in Philadelphia, opposite a pump, a girl, after filling
her pail, placed it upon the sidewalk. Godfrey, on turning toward it, saw
the sun reflected from the window on which he had been at work, into the
bucket of water, and his philosophic mind seizing upon the incident, was
thus led to combine the plan of an instrument by which he could draw the
sun down to the horizon, by a contrivance incomparably superior to any
that had ever before been used for the purpose of ascertaining angular
measurements.