LABOUR DIET 185 



lbs. when trotting the same distance at 7 miles an 

 hour. In the experiments of Grandeau and Leclerc, 

 a horse walking 12|- miles a day was kept in condition 

 with a daily ration of 19*4 lbs. of hay, while a ration 

 of 24 lbs. of hay was insufficient when the same dis- 

 tance was done trotting. A horse walking the above 

 distance, and dragging a load (additional work 1,943 

 foot-tons), was sufficiently nourished by a ration of 

 26*4 lbs. of hay; but a daily ration of 32'6 lbs.— all 

 that the horse would eat — was not enough to main- 

 tain the horse's weight when the same work was 

 done trotting. "When the horse is trotting, the in- 

 ternal work performed by the heart and by the res- 

 piratory muscles is much increased. The horse, when 

 trotting or galloping, also lifts his own weight at each 

 step, but allows it to fall again — the result appearing 

 only as heat. The temperature of the horse rises 

 with e:x:ertion, and much heat is lost by the evapora- 

 tion of water through the skin and lungs. The horse 

 at rest evaporated 6*4 lbs. of water, per day ; when 

 walking, 8*6 lbs. ; at work walking, 12*7 lbs. ; trotting, 

 13-4 lbs. ; at work trotting, 20-6 lbs. It follows, of 

 course, that a horse requires more water when at 

 work. The Paris cab horse, on a mixed diet, con- 

 sumed 2*1 of water to 1 of dry matter when at rest, 

 and 3*6 : 1 when in the cab. When fed with hay alone 

 the proportion was 3'3 : 1 at rest, and 4*3 : 1 when 

 with the cab. Horses of different disposition, and 

 different action when working, may require different 

 amounts of food to accomplish the same task. 



In order to calculate the quantity of food needed by 

 a horse performing a certain daily task, we need to 

 know the weight of the horse with harness, the draft 



