Sept. 8,1923 Determination of Surface Area of Cattle and Swine 429 
per cent. We did not have measurements of some of these animals, so 
were unable to apply the length-weight formula to all of them. In 19 
cases, however, we have the data to make a direct comparison between 
the Moulton and the length-weight formulae. Reference to Tables IV 
and VI shows that in these instances the latter formula gives a slightly 
smaller maximum error and a slightly smaller average error. The maxi¬ 
mum deviations from the measured values are +5.4 and —4.8 per cent. 
From the Moulton formulae it is seen that the maximum deviations are 
+ 2.8 and —7.6 per cent. The averages of all errors are, respectively, 
2.5 and 3.0 per cent. This comparison hardly does more than indicate 
that the length-weight formula is at least as accurate as any other 
hitherto proposed. 
With all the 37 cattle whose surface areas have been calculated by 
our formula (Table IV) the maximum errors were less than ±5.5 per 
cent. With all the 33 steers whose surface areas were calculated by the 
original Moulton formulae (Table VI) the maximum errors were +7.4 
and —9.0 per cent. The average errors were, respectively, 2.7 and 3.1 
per cent. It will be recalled (Table IV) that we modified the Moulton 
formula so that it could be applied to the live weight. The maximum 
error was ±10.2 per cent, and the average error was 3.7 per cent. 
A more refined statistical method is required to properly evaluate 
the two methods, but we do not consider such a procedure necessary. 
The formula we have proposed so far as it has been tested applies to all 
animals of the breed, and there is no opportunity for error in deciding 
which formula to use. Furthermore, it is more accurate than other 
formulae hitherto proposed. 
SUMMARY 
By using the weight and length of body, a more accurate formula has 
been developed for calculating the surface area of cattle and swine. 
The formula is: 
S = W' 4 X I/ 6 X K 
S is the surface area in square centimeters, W is the weight in kilo¬ 
grams, T is the length of the body in centimeters, and K is the constant 
217 for cattle and 175 for swine. The maximum error is less than ± 
5.5 per cent with either cattle or swine. 
LITERATURE CITED 
(1) Armsby, Henry Prentiss. 
1917. THE NUTRITION OF FARM ANIMALS. Xvii, 743 p., 45 fig. New York. 
Bibliographical footnotes. 
(2) Benedict, Francis G. 
19x5. factors affecting basal metabolism. In Jour. Biol. Chem., V. 20, 
p. 263-299. Bibliographical footnotes. 
(3) Bergmann, Carl, and Leuckart, R. 
1852. ANATOMISCH-PHYSIOLOGISCHE UEBERSICHT DES THIERREICHS. xiv, 69OP. 
438 fig. Stuttgart. 1852. 
(4) Dubois, Delafield, and Dubois, Eugene F. 
1915. the measurement of the surface area of man. In Arch. Internal 
Med., v. 15, p. 868-881. 
(s)-• 
1916. CLINICAL CALORIMETRY. TENTH PAPER. A FORMULA TO ESTIMATE THE 
APPROXIMATE SURFACE AREA IF HEIGHT AND WEIGHT BE KNOWN. In 
Arch. Internal Med., v. 17, p. 863-871, 1 fig. 
