ON THE MEASUKEMENT OF INTEENAL CAPACITY 
EEOM CRANIAL CIRCUMFERENCES. 
By M. a. LEWENZ, M.A., and KARL PEARSON, F.R.S. 
(1) In a memoir by Dr Alice Lee* on the reconstruction of the capacity of 
the skull from external measurements the following results were obtained : 
(a) Equations giving the probable capacity of the skull from a knowledge of 
the length, breadth and height for a number of races. 
(b) Equations giving the probable capacity from a knowledge of the product 
of length, breadth and height. 
(c) A demonstration of the small relationship between capacity and cephalic 
index. 
(d) A demonstration that the relationship between capacity and both horizontal 
and vertical circumferences varied much from race to race, even between allied 
races. 
The conclusions drawn from these results were : 
(i) That on the data dealt with there was no means of getting a small 
probable error in predicting the capacity of an individual skull from external 
measurements, but good results might be found from the average of series. 
(ii) That (6) gave a formula which changed less from race to race than (a), 
and the mean formula from (6) gave reasonably close results when we paid 
attention to sex difference. 
(iii) That the formula for the nearest allied race should, where possible, be 
selected, and failing any knowledge of evolutionary history then the mean formula 
based on (6). 
It will be clear that the above results emphasise the need for judicious caution 
in using the ' cranial capacity formulae, and also offer hints from experience to 
those anxious to discover new formulae. 
* Phil. Trans. Vol. 196, A, pp. 225—264. 
