THREE LECTURES 



ON 



THE PRINCIPLE OF LEAST ACTION IN NATURE, 

 ILLUSTRATED BY ANIMAL MECHANICS. 



LECTURE \,— Tuesday, May 2T^rd, 1871. 



Science of Anijnal Mechanics defined as the application of the priitciples 

 of Geometry and Mechanics to Comparative Ajtatomy. — General Prin- 

 ciple of Least Action, as observed in Astronomy and Physics. — Appli- 

 cation of this principle to Ani7nal Mechanics. — Illustration of the 

 Pleasures and Difficulties of the Study of Ani7nal Mechanics, fro7n the 

 Lecturer'' s Adventures iji Search of the Coefficient of Muscular Force. 



I TAKE it for granted that there is no one of those whom I now 

 address who has not read both with profit and pleasure GiUliver's 

 Travels. But of the many thousands that have read that charm- 

 ing book, there are very few that know the real circumstances of 

 the history of its production. It is only a fragment of a much greater 

 work which was contemplated and which the world has lost for ever — 

 a work which was to have been the combined result of the genius of 

 three of the most remarkable men that our country has produced ; one 

 an Englishman, another a Scotchman, the third an Irishman. More 

 than 150 years ago, in the good old times when Queen Anne reigned 

 in England, and science, literature, and art were patronised by her 

 court, three of the most remarkable men that ever lived in this city 

 were friends and companions. The Englishman was Pope, the Scotch- 

 man was Arbuthnot, and the Irishman — I may be permitted as a fellow- 

 countryman to say, greater than either — was our illustrious Swift. It 

 was proposed by Pope that a novel should be written by these three 

 men, which would have been a novelty not only in that age of litera- 

 ture but in our own, that the combined efforts of the genius of three 

 such men should be brought to bear upon the production of a work of 

 fiction. The fragments of that work of fiction remain at the end of 

 the large editions of Pope's works under the name of Memoirs of Mar- 

 tinus Scriblerus. Pope was to have taught Martinus Scriblerus litera- 



