SURFACE AREA OF BODY 



565 



8iiu-e the surface of a figure varies as the square, and that of volume as the 

 cube of its linear dimensions, it follows that 



S = K VF, 



where S = surface, F = volume and K = constant, or, as weight (W) varies 

 directly as volume, 



S = K l/W. 



Meeh, from sixteen experiments, suggested that K should be = 12-3 for 

 adults ; and Lissauer used the value 10-3 for children. The average error of 

 this calculation is about 16 per cent. 



The brothers Du Bois covered the body-surface of their subjects with 

 " tights " and applied melted paraffin. Paper strips were affixed to prevent 

 change of area during the process of removing the " shell." The model of 

 the surface, cut into pieces sufficiently snuill to be flat, was photographed upon 



?00 

 ISO 

 ISO 



: 170 



^ 130 



110 



100 



30 



SO 60 70 



Fig. 116. — Du Bois graphs for estimating tlie area of body-surface. 



squared paper of uniform thickness. The weight of each square on the paper 

 was known. The darkened portions of the paper were carefully cut and 

 weighed, and from this was calculated the area of body surface. The formula 

 resulting from this work involved nineteen measurements. From this they 

 liave evolved a two-measurement formula on which the appended chart is 

 based (Fig. 116). 



Sundry Conversion Factors 



Length 



Area 



Volume 



Weight 



Force 

 Velocity 



Inches to centimetres 



Square inches to square centimetres 



Cubic inches to cubic centimetres 



Gallons to litres 



Ounces to grams 



Grains to grams 



Pounds (avoirdupois) to kilos . 



Poundals to dynes 



Pounds weight to dynes 



Miles per hour to centimetres per second 



Multiply by 

 2-54. 

 64516. 

 16-387. 

 4-546. 

 28-349. 

 0-0648. 

 0-4536. 

 13,825. 

 4-45 X 105. 

 44-70. 



