Proceedings of the Farmers' Club. 479 



pounds resistance to the horses: 1st, the simple inertia of the mat- 

 ter constituting the machine; 2d, is the friction of the gearing 

 hn-gely increased by the arrangement for increasing the velocity; 

 3d, is the friction of the knife in its channel; 4th, is the friction of 

 the finger bar on the ground; 5th, is the resistance of the grass on 

 the fingers as they pass through it; and 6th, is the resistance of the 

 grass against the edge of the knife as the cut is made. Now, while 

 friction, as I said, is the means of procuring your power in first 

 moving your gearing, it is, from that point onward, the destroyer 

 of it. Therefore, let me urge you to increase it at the first point 

 and destroy it after that. And when you buy your next machine, 

 look out for this very thing. You see you must have weight to 

 create the power, but that weight does not increase the friction of 

 the gearing, or of any other part, if it rests only on the drivers; 

 and now you see why you and the boy both could make the machine 

 run through the bad places, while he alone could not. It was not 

 your skill, but your weight that did it. A bag of stones of the same 

 weight would have done just as well." 



" Yes, I see." 



"But that you and others may understand this matter better, I 

 will show you a few figures. The motion of your team and driving 

 w^heels is too slow to cut grass. Your knife must move quick and 

 spiteful, therefore velocity must be increased. Now, there is an 

 irrepealable law of nature, that if anybody wants velocity they 

 must pay for it in force or powder. Your initial velocity (that of 

 the teaui) is, we will say, three miles per hour. All horse power 

 machinery must conform to this speed. That is 26 1| feet in a 

 minute. On that space your thirty-two-inch drive-wheels make 

 thirty-three revolutions, and as your knife has a forward cut of 

 thi-ee inches at each stroke, it will make 1,056 strokes in 261| feet, 

 and in one minute; and as each stroke is four inches in length, your 

 knife has traveled 369 feet while the horses have moved 261^ 

 feet — a gain of over one-third in velocity, and a loss of one-third 

 of j'our force. 



" Next is friction in the gearing, which is often reckoned as equal 

 to one-third of the power; and here comes the other resistances 

 alluded to, so that finally your force, represented by 250 pounds 

 draft, and 500 pounds weight, which is pretty nearly all spent before 

 you get the edge of. your knife against the grass. And at that point 

 you need a force sufficient to cut an hundred and forty-four square 

 inches of grass (your bar being a four-feet bai'), and at the same 



