1896.] Relative Efficiency of Animals as Machines. 791 
Andre, 1890) represent in round numbers the calories per 
pound of the proximate principles of foods and tissues as fol- 
lows: proteids, 2500 calories; fats, 4200 calories; and carbo- 
hydrates, 1900 calories. 
For convenience of comparison, the energy in the table is 
represented in its equivalent of foot-tons of work; the energy 
expended in raising a weight of one ton one foot. 
Without an examination of other details this table would be 
misleading in its indications of the relative efficiency of the 
different classes of animals as machines for doing work. 
There are decided differences in the quality and quantity of 
feed consumed which should be taken into consideration, 
but we have no data for a quantitative estimate of the 
modifying influence of these different conditions which can 
only be noticed in general terms. For convenience of com- 
parison the most important facts relating to feed consumed 
may be summarized in tabular form. 
TABLE 3. 
Kind and quantity of feed consumed by fattening animals to produce 100 
pounds of increase in live weight, and feed of the cow for equivalent results in 
milk production. 
LJ 
| A Feed Consumed. 
i, A 
z | 2 $ 
sisig 3 
See rae re 
ee ee a E 
aA -£ 5 3 & 
B z 3 S z z A 
‘by by re) Ss oo > 
e A Le H S 3 
lbs. | Ibs. | Ibs. | Ibs. Ibs. lbs. lbs. 
Oxen 1109 | 68.6 | 218 9 600 PF 250 (oil p 3500 (swedes) 
Sheep 912 | 72.5 | 177 7.5 300 (clover 250 (oil cake 4000 (swedes ) 
Pigs 420 | 73.8 §2 37.0 500 (Barley meal.) 
“ Analyzed fat : 1. Bran. 2. Bean 
pes 478 | 71.4 | 100 | 7.7 and lentil meal. 3, 
pig Barley meal. 
Guernsey Apel 469 | 78 82 | 19.2 | 300 \ (clover and 210 \ mixed 420 ) corn 
Cow ay | 510] 88 81 | 21.5 | 182 j timothy) 213 j grain 868 j ensilage 
