112 
JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
the draught required for 2,000 lbs. on the narrow tires. When 
the surface was covered with two or three inches of very dry 
loose dust the results were unfavourable to the broad tire. On 
clay road, muddy and sticky on the surface and firm under¬ 
neath, the results were uniformly unfavourable to the broad 
tires. On the other hand, on clay road deep with mud and dry¬ 
ing on top, or dry on top and spongy beneath, numerous tests 
were uniformly favourable to the broad tire. The difference 
ranged from 52 to 61 per cent.; on the average about 8,200 lbs* 
could be hauled on the broad tires with the draught required for 
2,000 lbs. on the narrow tires. It was in this condition of dirt 
road that the broad tires showed to greatest advantage. As the 
road dries and becomes firmer the difference between the broad 
and narrow tires gradually diminishes, until it falls to about 25 
to 80 per cent, on dry, hard, smooth dirt, gravel, or macadam 
road, in favour of the broad tire. On the contiary, as the mud 
becomes softer and deeper,a condition is at length reached when 
the mud adheres to both types of wheel; here the advantage of 
the broad tires ceases entirely and the narrow tires pull mate¬ 
rially lighter. Generally it may be said that during the greater 
part of the year, and at times when the dirt roads are most in 
requisition and when their use is most imperative, the broad- 
tired wheels have a considerably lighter draught than the 
narrow-tired. 
Many tests on meadows, pastures, stubble land, corn ground, 
and ploughed ground in every condition, from dry, hard, and 
firm to very wet and soft, showed without any exception a large 
difference in draught in favour of the broad tires—a difference 
ranging from 17 to 120 per cent. The investigations further 
showed that six inches is the best width of tire for a combina¬ 
tion farm and road wagon, and that both axles should be the 
same length, thereby securing that the front and hind wheels 
shall run in the same track. This inquiry differs in character 
from some of the abstruse problems the solution of which is 
attempted at American experimental stations ; hut there can he 
no question as to its utility. 
