92 Report of the Committee of the DulUn Society 



And lastly, that wooden springs may be advantageously ap-» 

 plied to common carts. 



I have employed them in four one-horse carts, that have been 

 in daily use, for nearly four years. These carts are usually loaded 

 with fourteen hundred weight, and are much employed in car- 

 rying stones for the repair of roads. 



I have tried straight and elliptic springs, and have employed 

 both sorts successfully. 



A piece of common tough ash, five inches and a half deep in 

 the middle, two inches deep at each end, and three inches broad, 

 mounted on fixed shackles at one end, and with linking plates at 

 the other, is cheap and durable. 



The iron work of the shackles may last for many years. The 

 wooden springs may be renewed at any time for about ten shil- 

 lings ; and I am well satisfied that these springs will soon be in 

 conunon use among common carriers. 



I have the honour to be, gentlemen. 



Your obliged and obedient servant. 



Rich. L. Edgevvorth. 



XXIII. Eeport of the Committee of Natural Philosophy, ap- 

 pointed by the Duhlin Society, on the Experiments Jipon 

 P/heel-c<irriages, made ly Mr. Edgevvorth, on the 2Sik 

 (jf'JMay 1816, and succeeding Days, at the Dublin Society's 

 House, Kildare-street. 



jLJVi. Litton having kindly undertaken, at the request of this 

 committee, to take notes for them of the Experiments on Wheel- 

 carriages, 



Your committee proceeded to form a Report thereon ; but Mr. 

 Edgeworth having favoured them with some observations on 

 these experiments, your committee were of opinion that such 

 comments, with a statement of the experiments, in conformity 

 with the notes of Dr. Litton, would answer the object of the 

 Society better then a mere Report by the committee ; they there- 

 fore beg leave to lay the statement and the comments before tho 

 Society. 



The apparatus employed in these experiments was as follows: 

 A pulley seven feet in diameter, mounted upon a carriage which 

 can be drawn forward by men or horses. It turns upon a small 

 centre, and has been executed with such precision as to have 

 iicarlv the accuracy of a balance. Mr. Edgeworth has given 

 the name of peirameter to this machine. To determine the 

 Miction arising from the motion of its axis, and the bending of 



"the 



