596 



JOHN R. MURLIN 



The areas of the several members of the body as measured were then com- 

 pared with the areas as given by multiplying their lengths by sums of 

 measurements representing circumferences. For example, the area of 

 the arm was given by multiplying the length from the outer end of the clav- 

 icle to the lower border of the radius (F) by the sum of the three circum- 

 ferences at : upper border of axilla (G) ; largest girth of forearm (H) ; 

 smallest girth of wrist (I). This calculated area compared with the actual 

 area for several individuals gave a factor which, used with the product 

 first given, made up a so-called linear formula for the arm; thus: F 

 (G -f- H + I) 0.558. The several sub-formula3 added together could then 

 be employed for measuring the surface of the entire body. 



This method resembles the one proposed by^Roussy in which the surface 



Fig. 33. A method of calculating the surface area by treating the body as a series 

 of cylinders. The average is taken of 29 different circumferences (mean perimeter) 

 and this is multiplied by the sum of the several lengths. (Roussy. ) 



was given by multiplying the mean perimeter (Pm) by the mean peripheral 

 total height (Hm) ; thus S =Pm X Hm. The first factor was found by 

 taking the mean of 29 different circumferences (Fig. 33) while Hm is the 

 sum of 3 partial heights, (a) head, neck and shoulders; (b) trunk and 

 lower extremities ; (e) upper extremities. 



From his measurements Meeh devised a formula based upon the well 

 known relationship of surfaces to masses of similar solids ; namely, that the 

 former varies as the % power of the latter. By employing a constant, 

 12.3, Meeh found that the formula S = J/(w) 2 gave results within 7 

 per cent of those determined by actual measurement. DuBois found an 

 agreement between measured and calculated values for 5 cases within 

 2 per cent. Later his measurements were simplified and a formula con- 

 taining total height, weight and certain constant factors was devised. This 

 is known as the weight-height formula. A = W - 425 X H - 725 X 0., 



