THE ENGLISH PRECURSORS OF NEWTOX. 785 



his sagacity, and impulses from his zeal. Of all men who ever lived, 

 he was perhaps the most prolific in mechanical invention. New instru- 

 ments, or useful modifications of those already in use, flowed from him 

 by the dozen. An arithmetical machine, a triple writing-machine, a 

 deep-sea sounding machine, a wind-gauge, rain-gauge, hygrometer and 

 odometer, a system of telescopic telegraphy, a " water-poise," a " weath- 

 er-clock," and a species of microphone, were all due to his ingenuity; 

 besides important improvements in astronomical and other instruments 

 telescopes, quadrants, micrometers, diving-bells, barometers, ther- 

 mometers, and balances. He speculated curiously on memory, and 

 calculated the number of ideas of which the human mind is susceptible, 

 estimating it at three thousand one hundred and fifty-five million seven 

 hundred and sixty thousand ! He constructed a model for the rebuild- 

 ing of London after the great fire, which was approved, although not 

 adopted ; and was the architect of Hoxton Hospital and other build- 

 ings. He read before the Royal Society commentaries on Ovid's 

 ''Metamorphoses," Plato's "Atlantis," and Hanno's "Periplus," inter- 

 polating these critical excursions between geological theories and as- 

 tronomical observations. To him was due the ingenious idea of mea- 

 suring the force of gravity at different altitudes by the rate of vibra- 

 tion of a pendulum of a given length ; as well as the determination 

 (so far as the actual state of chemical knowledge permitted it to be 

 determined) of the true function of the air in combustion and respira- 

 tion. His zeal carried him to the length of making, in an exhausted 

 receiver, his own person the subject of his observations "the only 

 experiment of that kind," his biographer naively remarks, " I think 

 ever tried." 



At the present time, when weather prophecies have come to form a 

 recognized part of our complex social machinery, it would be ungrate- 

 ful to omit noticing that Hooke was the first to propose a scientific 

 system of meteorological forecasting. His scheme, as might be ex- 

 pected, had for its basis the close association (remarked by him among 

 the earliest) of changes of weather with barometrical variations ; 

 which, he writes to Boyle, October 6, 1664 



If it continue to do as I have hitherto observed it, I hope it wilLhelp us one step 

 toward the raising a theorieal pillar or pyramid, from the top of which, when 

 raised and ascended, we may be able to see tbe mutations of the weather at some 

 distance, before they approach us ; and thereby being able to predict and fore- 

 warn, many dangers may be prevented, and the good of mankind very much 

 promoted.* 



The means recommended by him for the furtherance of this note- 

 worthy object were the same in principle as those now in use at all the 

 meteorological observatories of Europe and America. Two hundred 

 years, however, had to elapse before they could be profitably employed. 



* Boyle's " Works," vol. vi., p. 492. 

 VOL. xvii. 50 



