Investigations Concerning the Horse. 



253 



According to King, 2 the draft required to haul a 4-wheel wagon 

 on various types of road is approximately as follows : 



Character of road Lbs. draft required per ton 



Common earth 75 to 224 



Gravel 75 to 140 



Macadam 55 to 67 



Woodblock 28 to 44 



Plank . 25 to 44 



This shows that it requires a draft of 75 to 224 Ibs., or a pull of 

 this amount as measured on a spring balance placed between horse 

 and load, to draw a load of a ton, including wagon, on a country 

 earth road, while on a plank road the draft is but 25 to 44 Ibs. 



The ox draws a load equal to the horse, but ordinarily at only 

 two-thirds the speed. A man's work is usually from one-sixth to 

 one-tenth of a horse power, or about one-fifth that of an average 

 horse. For a minute or two he can do a full horse power or more. 



391. Digestion trials. Since there have been relatively few diges- 

 tion trials with the horse, we are often obliged to use for this ani- 

 mal the coefficients of digestibility obtained with the ox or sheep. 

 (58) While the horse digests the easily digestible feeds about as 

 completely as do the ruminants, it falls below them in ability to 

 digest the more difficultly digestible feeding stuffs, as is shown in 

 the following table from Wolff: 1 



Digestion coefficients of common feeds for the horse and sheep compared. 



1 Land. Vers. Stat., 20, 1877; 21, 1878; Landw. Jahrb., 8, Sup. I 1879; 10, 

 1881; 12, 1884. 



