1004 



ANNUAL REPORT OP THE 



Off. Doc. 



required to eliminate this disadvantage. Three runs of the broad 

 tire over this track have in all cases been sufficient, however, to so 

 improve the road surface that both the broad and narrow tired 

 wagons passed over this road with less draft than the narrow tires 

 did in the original ruts. In addition to the saving of draft, the 

 road was made very much more comfortable and pleasant for the 

 users of light vehicles and pleasure carriages bj the few runs of the 

 six inch tire. Summing up all the tests on dirt roads, it appears 

 that there are but three conditions on which the broad tires draw 

 heavier than the narrow tires, viz., (1) when the road is sloppy, 

 muddy or sticky on the surface and firm or hard underneath; (2) when 

 the surface covered with a very deep loose dust and hard under- 

 neath; (3) when the mud is very deep and so sticky that it adheres 

 to the wheels of both kinds of wagons. It appears that the dust 

 must be extraordinarily deep to show a higher draft for the broad 

 than the narrow tires. The three conditions just named, therefore, 

 are somewhat unusual and of comparatively short duration. 

 Through a majority of days in the year and at times when the dirt 

 roads are most used and when their use is most imperative, the 

 broad tired wagons pull materially lighter than the narrow tired 

 wagons. 



IV. A large number of tests on meadows, pastures, stubble land, 

 corn ground, and plowed ground in every condition, from dry, hard 

 and' firm to very wet and soft, show without a single exception a 

 large difference in draft in favor of the broad tires. This difference 

 ranged from 17 to 20 per cent. 



V. It appears that six inches is the best width of tire for a com- 

 bination farm and road wagon, and that both axles should be the 

 same length so that the front and hind wheels will run in the same 

 track. 



