WIDTH OF TIEES ON WAGON WHEELS. 



Ill 



freight $1,000,000,000. It is claimed that this freight could be 

 moved the length of eight miles over first-class roads at an 

 average cost of eighty cents per ton, so that a saving of 

 $600,000,000 per annum might thus be effected. This sum 

 represents about one-fourth of the value, on the farms, of all the 

 farm products of the United States. An amount of about 

 $20,000,000 is paid out each year for the maintenance of public 

 roads outside the cities of the United States, yet after the expen- 

 diture of this sum these roads are no better at the end of the 

 year than at the beginning. All ratepayers are interested in re- 

 ducing this expense, provided the roads are not impaired in 

 efficiency. There exists a widespread belief that narrow wheels 

 are amongst the most destructive agents to streets, to macadam, 

 gravel, and dirt roads, and to the fields, meadows, and pastures 

 of the farm. The introduction in recent years of the wide-tired 

 metallic wheel at about the usual price of the ordinary narrow- 

 tired wheels has removed one very serious objection to the pro- 

 posed substitution of broad tires for the narrow tires hitherto 

 in use. In order to obtain reliable information on so important 

 a matter, numerous trials, extending over a year, so as to be 

 subject to all kinds of weather, have been carried out at the 

 Missouri Agricultural Experiment station. The draught or pull 

 was in all cases determined by means of a self-recording dynamo- 

 meter, and the net load in every trial was the short ton of 

 2,000 lbs. Contrary to what was anticipated, in the majority of 

 cases the draught was materially less when tires 6 in. wide were 

 used than when the tests were made with tires of the standard 

 width of H in. We give a brief summary of the results : — 



On macadam road, as an average of the two trials made, a 

 load of 2,518 lbs. could have been hauled on the broad tires 

 with the same draught as a load of 2,000 lbs. required on the 

 narrow tires. On gravel road, except when wet and sloppy on 

 the top, the draught of the broad-tired wagon was very much 

 less than that of the narrow-tired wagon ; averaging the six 

 trials, a load of 2,482 lbs. could be hauled on the broad tires with 

 the same draught as was required for a load of 2,000 lbs. on 

 the narrow tires. 



The trials on dirt roads gave varying results, according to 

 the condition of the road. Thus when it was dry, hard, and 

 free from dust, 2,530 lbs. could be hauled on the broad tires with 



