SURVEY OF THAT PART OF THE RANGE OF NATURE'S 

 OPERATIONS WHICH MAN IS COMPETENT TO STUDY. 



By G. Johnstone Stoney, M. A., D. Sc, F. R. S/ 



PREFACE. 



In the year 1860 Prof. Clerk Maxwell published, in the pages of the 

 Philosophical Magazine, a remarkable investigation, aided by which 

 the present Avriter 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 opera- 

 tions of nature, whether those carried on upon a large or on a small 

 scale. (See fig. 1.) 



At the suggestion of some scientific friends he now publishes the 

 diagram, in the hope that it may prove of equal assistance to others 

 ]>y contributing toward the formation of a correct estimate of wdiat 

 that little is which man can truly know, and of the contrast which 

 necessarih^ 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 anj^ clear human knowledge 

 concerning it must stop. 



DEFINITIONS. 



When interpreting nature's work, we are obliged frequently to speak 

 of high numl^ers and small fractions. To do this conveniently 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, 1000, etc. The uno-eighteen is to be 

 understood as the name of the eighteenth of this series; it is accord- 



^From a separate copy of the Scientific Proceedings of the Royal DubUn Society, 

 Vol. IX, No. 13, communicated by the author. Printed in The London, Edinburgh, 

 and Dublin Philosophical Magazine and Journal of Science, Fifth Scries, No.. 294, 

 November, 1899, pp. 457-474. 



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