230 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



" The very best and most effectual force in a man is that of rowing, 

 wherein he not only acts with more muscles at once for overcoming the 

 resistance than in any other position, but, as he pulls backward, the weight 

 of his body assists as a lever for continuous labor. 



" The horse is enabled to do more work on a surface of variable figure 

 than in a very level country. Horses do not wear well if all the roads they 

 draw upon be on an inclined plane or a fixed gradation. Ever}^ change of 

 figure in the surface brings into action another set of muscles, so that all 

 the muscles of the horse are in turn called upon to act on the varied sur- 

 faces, whereas those of a continuous figure appeal to one set of muscles 

 alone." 



Prof. Mapes. — This statement of Desagulier is not intended to show what 

 a horse may do by the exercise of weight and momentum combined, because 

 much more is accomplished by momentum than by any other force. For 

 instance, the stroke of a hammer upon the head of a nail exerts a greater 

 force than many tons of dead weight. So the horse, by the force of his 

 muscles, exerts the power of momentum, combined with his weight, and 

 accomplishes a task far beyond what he could by weight alone. There is 

 a book published by Mayhew, in this city, whiclr contains some details of 

 experiments made by the English Government with a cavalry regiment, 

 which ought to be in the hands of every farmer. It would teach them 

 much about the proper use of horses, and the adaptation of different 

 weights and forms to special work. A horse for speed requires to be of 

 very different construction from one for draft; and every horse requires a 

 particular regulation of the line of draft, to enable him to exert the great- 

 est power. 1 have seen men change a pair of tall horses for a small pair 

 without changing the draft-rod of the plow. In such a case there is a 

 great loss of power; so there is in the form of the plow; and it is impossi- 

 ble to tell by the appearance of the work of the horses, or the looks of th©- 

 plow, whether it will run easier than another or not, until both are tested 

 by the dynamometer, and the line of draft equally regulated to suit the size 

 of the horse. In work that is accompanied by quick movement, the weight 

 of a horse has little to do with his efficiency; but in a slow, heavy pull, 

 horses of a heavy weight are much the most suitable. [He illustrated this 

 point by an anecdote of exhibition of strength by a very strong man, who 

 could pull up from the floor, or pull across the room, any man of equal 

 weight with himself, however muscular. The Professor said to him, 

 *' Strong as you are, I can take another man as heavy as you under my 

 arm, and with the other hand drag you where I please." This was done 

 with perfect ease, very much to the astonishment of the exhibitor, who 

 thought he had encountered a man much stronger than himself. On the 

 contrary, it was the mere force of weight that enabled him to keep his feet 

 more firmly fixed on the ground.] It is just so with heavy horses. You 

 may observe them at a hard pull, in starting a heavy load, taking steps of 

 fcjcarcely an inch in length. For such work, the power of draft will not vary 

 five per cent, in horses of equal weight, no matter what their shape. The 

 weight has very much to do with their power in other work. For frequent 

 stopping and quick starting, a large horse is not suitable. In some farm 

 work we want intensity as well as dead weight. For the latter we want 



