34 RECORDS 



lation, its precession and nutation, and the lately discov^ered 

 wabbling of its axis of rotation are all known with a definite- 

 ness which is truly surprising when one considers its magnitude 

 and the degree of complexity of those properties. That the 

 eight thousand miles in its diameter should be known within a 

 few hundred feet, that the two hundred millions of square miles 

 in its surface should be known within a few hundred square 

 miles, or that the acceleration of gravity at any point on its sur- 

 face should be known within a few millimeters per second per 

 second, are results little short of marvelous when one reflects 

 that they have all been attained within the brief interval of two 

 hundred and fifty years. It would be quite wrong, however, to 

 consider these achievements of geodesy as marvelous from the 

 point of view of science. They are, rather, just such results 

 as persistent scientific investigation has always produced, and 

 such as we may safely predict will be uniformly produced by 

 persistent scientific investigation in the future. The element of 

 the marvelous comes in only when one takes account of the 

 fact that these grand results were attained by a very small num- 

 ber of men, mostly members of academies, struggling, like our 

 own, to maintain an existence, in whose work the general pub- 

 lic took little interest, and whose names, even now, are much 

 less known than the names of the obscure philosophers and the 

 obscene poets of antiquity. 



Geodesy is undoubtedly the most advanced of the sciences in 

 which measurement and calculation have attained a high order 

 of certainty. It has made modern commerce possible, and it 

 seems destined to play a still more important role than it has 

 hitherto in the advancement of terrestrial affairs. It has also 

 made modern astronomy possible, for the certainty of its data 

 enables us to measure not only the dimensions of the solar sys- 

 tem, but also the approximate dimensions of the visible universe. 



Not less important to the progress of science and to the gen- 

 eral advance in human enlightenment are the achievements of 

 the allied science of geology. It cannot boast, as yet, like 

 geodesy, of a high degree of precision in measurement and calcu- 

 lation, for it deals, in general, with phenomena which have not 



