THE CART 105 



clergymen. The travois came into general 

 use for transport. 



The next step was less obvious, an idea which 

 w^ould appeal to men of inventive minds ; and 

 I have noticed that it is onl}^ in civiHsation that 

 the inventor is treated as a public enemy. The 

 savage actually admires a man with new ideas. 

 The travois frame was a heavy drag, and the 

 draught pony was apt to delay the march. 

 Why not have a round log as a roller under the 

 trailing ends of the poles ? Too heavy. Cut 

 away the bulk of the roller, fining it down to a 

 mere axle bar, with a disc at either end to roll 

 along the ground. The larger the disc the 

 better it rolled, so disc v/heels were built, with 

 a hole in the middle into which the ends of the 

 axle bar were bolted. 



As one may see in the many countries where 

 disc wheels are used by farmers, the first idea 

 of lightening the disc was to cut out four large 

 holes, leaving the timber shaped like a rough 

 cross with a rim. But that cross was too weak 

 to carry weight, so its arms had to be strength- 

 ened with four spokes, lashed on with raw-hide ; 

 next the four spokes replaced the arms of the 

 cross, and a rim was built enclosed in a raw-hide 

 tyre. The raw hide, put on wet, and shrinking 

 as it dried, made a quite serviceable tyre. So 



