used in that sense, has no reference to th 
1 
166 On the Measure of’ 
its various bearings. We can form no notion 
of velocity, without taking time as an element 
of it.—As far as it relates, however, to me- 
chanical power, time would come under his— 
consideration chiefly in the following manner. 
If, for example, the object before him was to 
apply, to the best advantage, a given stream — 
of water in producing a mechanical effect, he 
would first ascertain the quantity of water _ 
passing in any given time, and the height of 
its fall. He would next inform himself whe- 
ther the effect to be produced should be con-: 
tinuous or intermitting in its duration. If con- 
tinuous, he would construct his machine of such 
dimensions as to receive and apply the power 
of the stream uniformly and constantly from _ 
hour to hour, and from day to day. But if it 
were required to produce an intermitting ef- 
fect, he would construct his machine of larger 
dimensions, in order to avail himself of the | 
quantity of water which might be treacveeidae aa 
during the time that no effect ‘was required to 
be produced; and he would take care to 
arrange and proportion the whole, so that no 
more people than necessary should be em- 
ployed in attending it. In the latter case, rl 
machine would be said to lie: tore powerful 
than in the former: but the word power, 
