242 MASSACHUSETTS AGRICULTURE. 



and, with them, also among the things that were. From their 

 perishable nature, they can never advantageously do more than 

 help the development of a new country, and in this, as well as 

 other States, are yearly becoming more and more impracticable 

 on account of the constantly increasing price of lumber. 



On the Resistance to Motion or the Force required to 

 MOVE Vehicles on different Kinds op Roads. 



Before, as well as since the introduction of railways, engineers 

 in England, Germany and France made many experiments on 

 the force necessary to pull different vehicles, at various speeds 

 over various surfaces. To enumerate the details of all these ex- 

 periments would be perhaps useless ; a few general results only 

 are here given. 



Experiments, as above indicated, were made by Edgeworth, 

 Count Rumford, Bevan, Macneill, Minard, Navier, Perdonnet, 

 Poncelet, Flachat, Morin, Kossak, Umpfenbach, Gerstner, and 

 no doubt others, a list of authorities that proves the subject to 

 have been well nigh exhausted. The experiments of Morin, 

 made in 1838-41, appear to have been made with a degree of 

 care and accuracy, leaving nothing more to be desired, and the 

 following table is an extract from his results,* and gives that 

 fraction of the weight of the vehicle and load, which is required 

 to move them on a level road : — 



* A full account of Morin's experiments on the resistance to motion of 

 vehicles, on the wear caused by different vehicles on roads and on the loads 

 different vehicles should carry so as to pi'oduce the same wear, may be 

 found in Morin, Experience sur le tirage des Voitures, Paris, 1842. 



