[78] 
SOUL 
SURVEY OF THAT PART OF THE RANGE OF NATURE’S 
OPERATIONS WHICH MAN IS COMPETENT TO STUDY. 
By G. JOHNSTONE STONEY, M.A., D. 8&c., F.B.S. 
[Read Marcu 22; Received for Publication May 1; Published Aveusr 18, 1899.] 
PREFACE. 
In the year 1860, Professor Clerk Maxwell published, in the pages 
of the Philosophical Magazine, a remarkable investigation, aided 
by which the present writer, in that year, drew up for his own 
information the scheme of magnitudes described in the following 
pages, from the use of which he has ever since derived advantage 
when studying the operations of Nature, whether those carried on 
upon a large or on a small scale. (See fig. 6, opposite p. 96). 
At the suggestion of some scientific friends, he now publishes 
the diagram, in the hope that it may prove of equal assistance to 
others, by contributing towards the formation of a correct estimate 
- of what that little is which man can truly know; and of the con- 
trast which necessarily prevails whenever the boundless range 
both in time and space of each actual operation in nature, is 
considered in its relation to the limits in both directions at which 
any clear human knowledge concerning it must stop. 
DEFINITIONS. 
When interpreting Nature’s work, we are obliged frequently 
to speak of high numbers and small fractions. ‘To do this conve- 
niently we shall employ the affix -o to signify a decimal multiple. 
Thus, a uno will mean some decimal multiple of the arithmetical 
unit, that is, some member of the series 10, 100, 1,000, &c. The 
uno-eighteen is to be understood as the name of the eighteenth oi 
