A 



B 



E. 



80 



The wei'^lit of the load 31b. The weight of the load, wheel and carriage, &c, 4lb. 



The fcale and weight defcended fix inches and two-tenths every revolution of the roller. 



The diameter of the wheel was two inches nine-tenths, and the circumference of the circle upon which the wheel ran was ten feet three inches and a quarter. 



EXPERIMENTS. 



A vane of tin, 11 inches long, and 5 and i broad, faftened to 

 an arm, projeding from the roller, to regulate the motio'n of 

 the machine by its relirtancc againft the air ; the extrenaity ot 

 the vane 21 inches from the centre of the roller, made 



The fame as No. i, with the wheel running upon the iron 

 circle ._------- 



The fame as No. 2, but with an obftaclc of i inch high, placed 

 on the road _..-.--- 



The fame as No. 2, but with two obftacles 



Ditto, with two inclined planes, i inch high, -J inch long, inftead 

 of the obftacles ------ 



Springs placed between the weight and the wheel, two obftacles 

 i inch high, placed on the road _ - - - 



Same as No. i, with half the velocity - - - 



Same as No. 4, with half the velocity .- - - 



Same as No. 6, with half the velocity - - - - 



Turns. 



20 

 20 



20 

 20 



20 



20 

 10 

 10 

 10 



Time, 



Seconds. 



20 



20 

 20 



2D 



20 

 20 

 20 

 20 



IFeight. 



lb. oz. 



4 10 



12 O 



20 O 



9 8 



I 6 



7 8 



3 8 



OBSERVATIONS. 



The refiftance of the air againft the vane, and againft all the 

 moving parts of the machine, was equal to - - - 



This weight muft therefore be dedufted from the weights ufed 

 in the fublequent experiments. 



41b. 10 oz. being deduded for the refiftance of the air from 

 5 lb. looz. the remainder was the refiftance occafioned by the 

 motion of the wheel on the fmooth board 



The refiftance of an obftacle of i inch high 



The refiftance of two obftacles of i inch high 



The refiftance of inclined planes inftead of abrupt obftacles 



The refiftance of two obftacles i inch high when fprings were 

 ufed, only .-.--- 



Refiftance of the air to half the former velocity 



Refiftance of two obftacles with half the former velocity 



Refiftance of ditto with fprings - - - " 



