WHEEL CARRIAGES. 101 



on spiral wings ; the wings and feathers of which 

 are set with stones of various colours, and appear 

 as if flying away with the chariot, which, from 

 another secret motion, is contrived to run in a 

 straight, circular, or any other direction. A boy, 

 that lays hold of the chariot behind, seems also to 

 push it forward. Above the umbrella, are flowers 

 and ornaments of precious stones, and it terminates 

 with a flying dragon set in the same manner. The 

 whole was of gold, most curiously executed, and 

 embellished with rubies and pearls. 



WHEEL CARRIAGES. 



It is very probable, that, in the infancy of the 

 arts, sledges were used before wheels were in- 

 vented, or at least before the application of them 

 became general. Even now, indeed, sledges are 

 employed for certain purposes in our own country, 

 notwithstanding the number of wheel carriages 

 used in it from time immemorial. 



In some of the cold climates, where ice is to be 

 met with in considerable quantity, and the ground 

 is covered with frozen snow for a great part of the 

 year, sledges are much in use, and run upon the 

 smooth surface of the earth with as great ease as 

 wheels run upon the ordinary ground. Upon very 

 smooth ice, indeed, or upon any other body per- 

 fectly smooth, wheels would not turn readily ; for 

 the only reason why they turn in the ordinary way, 

 is the continual inequalities they meet with. 



On common roads, wheels meet with obstruc- 

 tions at the bottom, which retard that part ; the 

 upper part is in consequence drawn forward, and 

 a circulating motion takes place. 



h 3 



