84 



SCIENCE. 



[N. S. Vol. XIV. No. 342. 



discover. He observed at once that by its 

 different manifestations his physical comfort 

 was materially affected, and it did not take 

 long for him to learn that certain sequences 

 of sensation, of one sort or another, followed 

 certain manifestations occurring singly or 

 in combination, and then that the order of 

 many such manifestations could be con- 

 trolled by him at will, while that of multi- 

 tudes of others could not be so controlled at 

 first, their methods and causes not being 

 appreciable by his unassisted senses. 



But until about three hundred years ago 

 there does not seem to have been any sys- 

 tematic and well-directed effort to investi- 

 gate the reasons why material changes oc- 

 curred naturally, or how certain changes 

 could be artificially produced with certainty. 



To discover the sequence of natural 

 events is first of all an empirical task : 

 facts must be observed systematically, and 

 recorded, and then their combinations 

 reasoned upon. Hypotheses can then be 

 formed as to the probable effects of slightly 

 different collocations and sequences of 

 events, and these subjected to experiment 

 and computation. An hypothesis cannot 

 be established as a scientific fact until it has 

 been verified by observation and also proved 

 to be in accordance with mathematical laws. 

 Tennyson's apothegm, that ' knowledge 

 comes, but wisdom lingers,' is profoundly 

 true. 



Now, up to the beginning of the seven- 

 teenth century of the Christian era, there 

 had been no organized physical experimen- 

 tation, on a comprehensive scale, and intel- 

 ligent reasoning therefrom. The specula- 

 tions as to the laws of nature which had 

 been made from time to time had been purelj^ 

 efforts of the imagination, and were unsus- 

 tained by either practical demonstration 

 or analytical reasoning. Various hypoth- 

 eses had been framed, on insufficient or 

 incorrect premises, and some of them had 

 been so near the truth as actually to delay 



the progress of the truth, by the appearance 

 of exactness in the reasoning from them, up 

 to a certain point. 



Really, the civil engineer had been prac- 

 ticing his art and directing the forces of 

 nature for the use and convenience of man, 

 but without any conception of what those 

 forces were, or how they acted, or of why 

 he did anything, or what the result of it 

 would be, unless he had done the same 

 thing before in the same way. He did not 

 know that the earth moved, and he had no 

 idea why or at what rate a stone fell to the 

 earth, or water ran down hill. He had no 

 measure of heat Or light, and used no power 

 but that which the muscles of an animal 

 produced. And yet he had built the Pyra- 

 mids, the Parthenon and the Pantheon ; 

 had constructed aqueducts, canals and 

 sewers ; had regulated and maintained the 

 rivers of China for thousands of years ; and 

 had just been recognized, on account of his 

 labors in protecting the lowlands of Holland 

 and the shores of Italian rivers from the 

 encroachments of the water, as holding a 

 distinct rank among the workers of the 

 world. 



Of the application of the forces of nature 

 to aiding his labors, he seems to have been 

 ignorant, except hy the use of a flowing 

 stream to turn a wheel. The earliest re- 

 corded application of this mode of producing 

 power in England was in 1582, when Peter 

 Moryss, a Hollander, procured from the 

 City of London a franchise for five hundred 

 years for supplying water to the city by 

 pumping from the Thames, using a wheel 

 driven by the ebb and flow of the tide under 

 London Bridge. 



With the beginning of the seventeenth 

 century, the world entered on a new era of 

 science, theoretical and applied. The casual 

 observation hj a little child of the curious 

 optical effect obtained by looking through 

 two pieces of glass led to the invention of 

 the telescope and the microscope, which 



