DYNAMICS. ,57 



5? t for the measure of it, and therefore to suppose 

 it proportional to the velocity simply. This is the 

 only way in which the language of the science can 

 be rendered perfectly consistent and free from am- 

 biguity. But as the distance to which a body goes 

 before a given resistance destroys its motion, is often 

 an object of inquiry, it may be proper to consider 

 that distance as a measure of a certain power re- 

 siding in the moving body. It has been proposed 

 to distinguish this power by the term Impetus. 



b. This part of Dynamics would lead to the conside- 

 ration of Central Forces ; but as this is a subject of 

 some difficulty, and is most interesting when con- 

 nected with astronomy, we shall defer treating of it 

 till we enter on the explanation of the Planetary 

 Motions. 



MECHANICS. 



