426 
Journal of Agricultural Research 
Vol. XXV, No. 10 
the unknown values. We were disappointed in one respect—the values 
obtained for the exponents were not as uniform as we had hoped. Our 
final procedure, therefore, was to take the values most frequently occur¬ 
ring and by actual trial to determine which gave the least variable values 
for K. The value then assigned to K was the mean of the extremes. 
The equation finally chosen is: 
S = W' 4 XL 6 XK 
K is 217.02 for cattle and 175 for hogs. S is the surface area in square 
centimeters. W is the weight in kilograms, and L is the length of the 
body in centimeters. This formula is, of course, identical in principle 
with the Du Bois height-weight formula for man. 
In order to test the relative usefulness of our method, the surface 
areas of our animals have been calculated both by the length-weight 
formula and the Meeh formula. The calculations for cattle include also 
the formula of Moulton as developed for thin animals. His calculations 
were based on the empty weight, so we assumed that the formula would 
apply to the live weight if a suitable constant were chosen. The constant 
selected is 1,081. The Moulton formula for fat animals was not used 
because we were not certain that any of our animals were sufficiently fat 
to be classed in that group. It would seem that the possibility of error 
in judgment as to which to use is an element of weakness in the Moulton 
formulae, though we doubt whether it would lead to a gross error. 
Table IV .—Surface area as measured and as calculated for cattle 
Surface as calculated. 
No. of animal. 
Surface as 
measured. 
S=W-*XL-«XKi“ 
S=W^XK 3 “ 
S-W^XK 3 “ 
Area. 
Error. 
Area. 
Error. 
Area. 
Error. 
Sq. cm. 
Sq. cm. 
Per cent. 
Sq. cm. 
Per cent. 
Sq. cm. 
Per cent. 
.. 
55,407 
56, 77 o 
+2.5 
55 ,692 
+0.5 
56,924 
+2.7 
5 °,583 
53,193 
49,984 
+ 5-2 
54 ,509 
+ 7-8 
55,790 
51,638 
+10.3 
.. 
47 ,721 
4-4.8 
50,194 
+5.2 
+8.3 
4 . 
46,521 
48,812 
+4.9 
48 ,947 
+ 5-2 
50,434 
+8.4 
5 . 
45 ,I 7 i 
44,900 
—0.6 
44,522 
-1.4 
46,148 
+ 2*2 
6. 
12,466 
12,702 
+ 1-9 
11 ,743 
- 5-8 
13,230 
+6.1 
7 . 
23,581 
23,444 
—0.6 
20,944 
— 11.2 
22,758 
- 3*5 
8. 
49,990 
48,801 
-2.4 
51,152 
+2.3 
52,563 
_ + 5 *i 
528. 
64,028 
64,229 
+0.3 
62,050 
- 3*1 
62,996 
—1.6 
572 . 
45,176 
43,750 
“ 3-2 
44 ,668 
— 1.1 
46,290 
+2.5 
573 . 
571 . 
574 . 
41,140 
47 ,138 
38,236 
39 , 4 U 
44,843 
37,240 
—4.2 
—4.9 
—2.6 
37 , S31 
43,122 
34,422 
~8.o 
-8.5 
—10.0 
39,613 
44,786 
36,257 
- 3-7 
-5.0 
- 5-3 
575 . 
40,236 
39,525 
— 1.8 
36,551 
—9.2 
38,355 
- 4-7 
577 . 
55,664 
53 ,152 
- 4-5 
51,900 
-6.8 
53,283 
- 4-3 
578 . 
579 . 
48 ,957 
53,190 
46,336 
51,839 
- 5-4 
-2.5 
45,540 
49 , 78 o 
-7.0 
-6.4 
47,136 
51,240 
- 3-7 
- 3-7 
585 . 
49,046 
48,698 
—0.7 
46,403 
- 5-4 
47,973 
—3.3 
503 . 
509 . 
36 ,143 
49 , 701 
36, 79 i 
49 , 4 i 8 
+ 1.8 
—0.6 
34,005 
46,904 
~ 5*9 
— 5-7 
35,846 
48,458 
-0.8 
- 2-5 
197 . 
52,810 
52,340 
51,438 
-0.9 
49,919 
- 5-5 
51,372 
49,690 
-2.7 
507 . 
50,175 
+2.5 
48,177 
—4.0 
-0.9 
502. 
51,038 
53,366 
4 - 4-6 
51,562 
+ 1-0 
. 52,956 
+3*8 
541 . 
38,036 
36,975 
-2.8 
38,302 
+0. 7 
J 40, 079 
+ 5*4 
527 . 
66,343 
67,973 
+ 2-5 
72,405 
+9.2 
h 72,803 
+9.7 
515 . 
58, 846 
61, 737 
+ 4.9 
66,6x2 
+ 13.2 
b 67, 327 
+ 14-4 
48. 
62,038 
6 $,145 
+ 5-0 
70,500 
+ 13-6 
b71,006 
+14-4 
501 . 
64,635 
66,679 
+ 3-2 
74,737 
+ 15-6 
h 74 > 9 Q 8 
592 . 
34,345 
34,214 
-0.4 
28,961 
- 15*7 
30,836 
—10.3 
558 . 
20,189 
20,586 
+ 2.0 
18,415 
-8.8 
20,170 
0.0 
538 . 
524 .i. 
29,211 
46,417 
28,332 
45,373 
- 3 *o 
—2.2 
25,982 
41,245 
48 ,177 
—11.1 
— 11.1 
27,853 
43,955 
—4.6 
- 7-5 
500. 
54 ,148 
51,437 
“ 5-0 
— IJ.O 
49,690 
— 8.2 
540 . 
26,068 
25,902 
—0.6 
23, 73 * 
—90 
25,585 
—1.8 
595 . 
525 . 
36 ,555 
39,955 
36,639 
39,864 
+0.2 
—0.2 
33,502 
36 ,792 
-8.4 
— 7*9 
35,347 
38 ,593 
- 3-3 
— 3*4 
523 •• .. 
46,827 
44,564 
- 4-8 
42,675 
-8.9 
44.351 
- 5*3 
“Constants: Ki«=2i7.o2; K2=8i2; K3 =i,o8j, 
6 These animals were very fat when measured, so this formula is not expected to apply to them. They- 
are included merely to complete the table. 
