Mr. Blake's Reply to Mr. Quinby. 353 



of time whatever ; and if we could even suppose this result to 

 take place without the lapse of time, it would still require the 

 same quantity of power to produce it. 



For the illustration of these points, with regard to the men- 

 suration of mechanical power, let us take a familiar example 

 in the mensuration of other objects. The distance between 

 the cities of New- York and New-Haven, by road, is the same, 

 whether the road be wide or narrow ; and if we could even 

 suppose the road to have no width at all, the distance would 

 still be the same. In measuring the road for the purpose of 

 ascertaining the distance, it is the length of the road, which 

 is to be measured, and which is the quantity sought ; and of 

 this quantity, the width of the road is not an attribute, how- 

 ever inseparable width may be from the existence of the road. 



It is believed, that Mr. Quinby will now perceive, that 

 time has nothing to do with the quantity, of which the second 

 example requires a mensuration. But as these distinctions 

 can not be too much insisted on, for the sake of further illus- 

 tration, and also to show the analogy, which subsists between 

 the mensuration of power, under the distinctions pointed out, 

 and the mensuration of other objects, let us take another 

 familiar example. Suppose I should say to Mr. Quinby, that 

 I have a board, which will exactly reach from a certain point 

 to a certain other point, which two points are 3| yards asun- 

 der. Mr. Quinby, upon this statement of the case, immedi- 

 ately perceives that I have furnished him with data for deter- 

 mining the length of the board, and replies, that it must be 

 1 feet long. And this is all he can determine with regard 

 to the dimensions of the board, notwithstanding it is certain 

 that the board must have width and thickness, as well as 

 length. Suppose I should then say, that the board is also 1 2 

 inches wide, and require, as before, the measure of it. He 

 will now determine the area of the board, and reply, that it 

 measures 10 square feet. I next say, that the board is also 

 one inch thick, and require again its measure. He will now 

 determine the solid contents, and reply, that it measures \ f of 

 a cubic foot. Thus, in the mensuration of the board, three 

 different quantities have been obtained, corresponding with 

 the data respectively furnished. Just so, the three examples 

 for the mensuration of power, require the measurement of 

 three different quantities, corresponding respectively with the 

 data furnished by the example ; and, as in the case of the 

 board, the three different quantities all arise in the mensura- 



Vol. XIII.— No. 2. 20 



