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Proceedings of the Royal Society of Edinburgh. [Sess. 
(2) Theoretical. 
Figs. 14, 15, and 16 exhibit the results calculated from the hypothesis 
of zonal distribution. The ordinates have the same signification as in 
fig. 8, which dealt with double parallels of latitude illustrative of the 
demagnetised condition. In the present case the polarity of the residual 
magnetisation (positive) is represented by single zones of north latitude as 
shown by the arrows. The zones contain an equal number of molecules 
and the parallels bounding each zone are given in the diagrams. 
The curves must be regarded as a first approximation, dealing as they 
do with single zones departing from a narrow equatorial belt, not from 
a broad equatorial belt between wide parallels found to be typical of 
complete demagnetisation by reversals. Nevertheless the general similarity 
