INTRODUCTION. 



I In the astronomical part only, some o bs^rjatjons occur, i 

 mathematical evidence ; here, however, it was as impracticable as ~itl 

 would have been useless to attempt to enter into investigations, which in 

 many instances have been extended far beyond the limits even of Newton's 

 researches. But for the sake of those who are not disposed to undertake the 

 labour of following, with mathematical accuracy, all the steps of the 

 demonstrations on which the doctrines of the mechanical sciences are 

 founded, I shall endeavour to avoid, in the whole of this course of lectures, 

 every intricacy which might be perplexing to a beginner, and every 

 argument which is fitter for the closet than for a public theatre. Here I 

 propose to support the same propositions by experimental proofs : not that 

 I consider such proofs as the most conclusive, or as more interesting to a 

 truly philosophic mind than a deduction from general principles ; but because 

 there is a satisfaction in discovering the coincidence of theories, with 

 visible effects, and because objects of sense are of advantage in assisting 

 the imagination to comprehend, and the memory to retain, what in a more 

 abstracted form might fail to excite sufficient attention. 



This combination of experimental with analogical arguments constitutes 

 the principal merit of modern philosophy. And here let the citizen of the 

 world excuse the partiality of an Englishman, if I pride myself, and con- 

 gratulate my audience, on the decided superiority of our own country, in 

 the first establishment, and in the subsequent cultivation, of the true phi- 

 losophy of the operations of nature. I grant that we have at times been 

 culpably negligent of the labours of others ; that we have of late suffered 

 our neighbours to excel us in abstract mathematics, and perhaps, in some 

 instances, in patient and persevering observation of naked phenomena. We 

 have not at this moment a taagrauge or a Laplace/: what we have I do not 

 think it necessary to enumerate : but there is a certain combination of 

 theoretical reasoning with experimental inquiry, in which Great Britain, 

 from the time of the reformation of philosophy, has never been inferior to 

 any nation existing. I need only refer to the Transactions of the Royal 

 Society, for abundant instances of the mode of investigation to which I 

 allude ; and I will venture to affirm, that their late publications are equal 

 in importance to any that have preceded. It was in England that a Bacon 

 | first taught the world the true method of the study of nature, and rescued 

 science from that barbarism' in which the followers of Aristotle, by a too 

 servile imitation of their master, had involved it ; and with which, even of 

 late, a mad spirit of innovation, under the name of the critical jjhilqsophy, 

 has, in a considerable part of Europe, again been threatening it. It was in 

 this country that Newton advanced, with one gigantic stride, from the re- 

 gions of twilight into the noon day of science. A Boyle and a Hooke, who 

 would otherwise have been deservedly the boast of their century, served but 

 as obscure forerunners of Newton's glories. After these, a c'ro'wd of eminent 

 men succeeded, each of great individual merit ; but, absorbed in the prose- 

 cution of the Newtonian discoveries, they chose rather to be useful by their 

 humble industry than to wander in search of the brilliancy of novelty. It 

 is difficult to judge of our coj,emporaries ; but we appear at present to be 

 in possession of more than one philosopher, whose names posterity will be 



