GRAVITATION. 91 



cease. It gives new impulses every moment, which 

 come in to increase the last acquired velocity. Now it is 

 this constant and regular acceleration, which gives to the 

 motion of falling bodies their chief peculiarity, and from 

 this it results, that at the end of 1, 2, 3 and 4 seconds, 

 the spaces through which the body will fall, will be as .1, 

 4, 9 and 16, which are the squares of the numbers repre- 

 senting the time. 



It has been found by experiment, that a body falling 

 freely, passes through 16 feet and 1 inch in one second ; 

 in 2 seconds it will pass through 4 times that distance ; 

 in 3 seconds 9 times, and so on. From this, a little 

 arithmetical ingenuity will easily calculate the distance, 

 through which a heavy body will fall, in any number of 

 seconds. The height of a precipice, or the depth of a 

 well may be, by the assistance of a stop watch, measured 

 on this principle, though the result may not be very ac- 

 curate. 



DISCOVERY OF THE PRINCIPLE OP GRAVITATION : SIB 

 ISAAC NEWTON. 



The subject of gravitation suggests to the mind of 

 every reader, the name of the great English Philosopher, 

 Sir Isaac Newton. We cannot more appropriately close 

 this treatise, than by describing some of the leading in- 

 cidents in his life. 



He was born about three hundred years ago, in Lin- 

 colnshire, England, at a place called Woolsthorpe. He 

 was so small, and feeble in his early infancy, that little 

 hope was entertained of his life. This has been the case 

 with many individuals, who afterwards attained to high 

 intellectual eminence. His father died before his birth, 

 but his mother did all in her power to provide for him 

 the means of education. At one of his schools, he dis- 

 played a very singular capacity for mechanical contri- 

 vances. ' By means of little saws, hatchets, hammers, and 

 all sorts of tools, he made models of wood, when his com- 

 panions were at play ; and such was his dexterity, that he 

 constructed a wooden clock, and a good model of a 

 windmill, which was erected about that time in his neigh' 

 borhood. Into this model he sometimes put a mouse, 



