ANNUAL ADDRESS OF THE PRESIDENT, 
WILLIAM HARKNESS. 
Delivered December 10, 1887. 
THE PROGRESS OF SCIENCE AS EXEMPLIFIED IN 
THE ART OF WEIGHING AND MEASURING. 
Two centuries ago the world was just beginning to awaken from an 
intellectual lethargy which had lasted a thousand years. During all 
that time the children had lived as their parents before them, the 
mechanical arts had been at a standstill, and the dicta of Aristotle 
had been the highest authority in science. But now the night of 
medievalism was approaching its end, and the dawn of modern 
progress was at hand. Galileo had laid the foundation for accurate 
clocks by discovering the isochronism of the simple pendulum; 
had proved that under the action of gravity light bodies fall as 
rapidly as heavy ones; had invented the telescope and with it dis- 
covered the spots on the sun, the mountains on the moon, the sat- 
ellites of Jupiter, and the so-called triple character of Saturn; and 
after rendering himself immortal by his advocacy of the Copernican 
system, had gone to his grave, aged, blind, and full of sorrows. His 
contemporary, Kepler, had discovered the laws which, while history 
endures, will associate his name with the theory of planetary motion, 
and he also had passed away. The first Cassini was still a young 
man, his son was a little child, and his grandson and great-grand- 
son, all of whom were destined to be directors of the Paris Observa- | 
tory, were yet unborn. The illustrious Huyghens, the discoverer 
of Saturn’s rings and the father of the undulatory theory of light, 
was in the zenith of his powers. The ingenious Hooke was a little 
younger, and Newton, towering above them all, had recently in- 
vented fluxions, and on the 28th of April, 1686, had presented his 
Principia to the Royal Society of London and given the theory 
of gravitation to the world. Bradley, who discovered nutation and 
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