774 VETEEINAEY HYGIENE 



These results are perhaps of more interest from a 

 mihtary than from a civil point of view. If a hunting 

 man buys a horse that is not up to his weight he is the 

 only person that suffers inconvenience ; but the matter is 

 very different when the effective weight-carrying power of 

 military horses is concerned. It then becomes a funda- 

 mental question affecting the entire usefulness of the ' eyes 

 and ears ' of an army, and the matter will from this point 

 of view be alluded to again in dealing with army horses. 



The amount of weight which a horse is capable of 

 pulling is much easier of determination. All that is 

 required is a dynamometer. Yet reliable observations have 

 hitherto not been very numerous. 



Watts' classical experiment of a horse pulling 150 lbs. a 

 distance of 220 feet every minute for ten hours a day, has 

 been generally accepted as the normal capabilities of a 

 horse, whereas it is not so. That this force can be exercised 

 is undoubted, but it is far too high a standard to adopt for 

 general work. 



The first thing to ascertain is the extreme limit of a 

 horse's power — his maximum muscular effort — and in a 

 series of observations on this point which we have under- 

 taken,* it was found this varied from 65"6 per cent, of the 

 body-weight to 78"5 per cent., the former group being 

 recorded as indifferent pullers, the latter as excellent. If, 

 therefore, we say the maximum muscular effort a horse 

 can exert varies from 68 per cent, to 78 per cent, of his 

 body-weight, it will not be far from the truth. So that a 

 horse weighing 1,000 lbs. can exert a steady pull of from 

 680 lbs. to 780 lbs. for a few seconds ; it is, in fact, the 

 limit of his power. 



The body-weight of a London dray horse is from 18 to 

 21 cwt., while that of a Glasgow horse is from 16 to 18 cwt.t 



The next point for consideration is what proportion of a 

 horse's body-weight may be effectively utilized in draught, 



* ' Maximum Muscular Effort of the Horse ' : Journal of Physiology, 

 vol. xix., 1896. 



t ' Heavy Horses ': Live StocJc HandbooT:, No. 3. 



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