354 THE POPULAR SCIENCE MONTHLY. 



great revolution by so many other able thinkers and workers, 

 whose names will never survive into future ages. 



Every now and then a great crisis occurs in the world's history 

 when some new advance, rendered inevitable by the slow growth 

 of the past, halts for a moment on the threshold of realization. A 

 genius is needed to make the advance ; but the genius is always 

 then and there forthcoming from the vast reservoir of potential 

 greatness forever present in all civilized countries. It is the 

 noble chance that brings forth the noble knight : the men lucky 

 enough to take the tide at its flood, lucky enough to reach matu- 

 rity at the very moment of the turn, achieve a visible success per- 

 haps somewhat disproportioned even to their real and undoubted 

 merit. Or rather, they throw unduly into the shade the men who 

 precede and the men who come after them. There are moments 

 when good workers can not fail to obtain wonderful results, be- 

 cause those results are then and there almost forced upon them 

 by the circumstances of science. There are moments when good 

 men must almost of necessity become hewers of wood and drawers 

 of water for the architectonic generation that will come after 

 them, because the last generation has built up all the materials then 

 available, and new stores must needs be collected before another 

 story can possibly be added to the whole vast fabric of scientific 

 thought. Every mighty outburst is followed close by an apparent 

 lull, a lull during which the forces at work are expending them- 

 selves rather upon preparation than upon actual performance, 

 upon providing fresh facts and hyj)otheses and suggestions rather 

 than upon co-ordinating and interpreting the old ones. 



Hence it may often happen that certain names, popularly re- 

 garded as small, may really belong to greater individualities and 

 greater intellects than certain other names of critical and, so to 

 speak, nodal interest. The man who comes at the exact turning- 

 point ]performs in one sense a greater work than the man, however 

 able, who chances to light upon one of the ebb-tides or intervening 

 periods. Geology supplies us in our own day with an excellent 

 example. Lyell's name will always be held to tyjDify the evolu- 

 tionary impulse in geology, as Darwin's does in biology, Spencer's 

 in psychology, and Laplace's in astronomy. But of these four 

 central names, Lyell's stands distinctly on a much lower mental 

 level than the remaining three. On the other hand, we have now 

 among us a geologist of the very highest ability, a man Vv'ho has 

 devoted to his chosen science a breadth and profoundness of cos- 

 mical grasp never before associated with it — I mean, of course, 

 Archibald Geikie. It is impossible for any competent critic to 

 look at Geikie's " Text-Book of Geology " by the side of Lyell's 

 " Principles and Elements " without immediately recognizing the 

 immense difference of mental stature between the two men. I do 



