32 PLEASANT WAYS IN SCIENCE. 



ably illustrates the value of cyclic relations. Men might 

 have gone on for centuries, we may conceive, noting the 

 recurrence of seed-time and harvest-time, summer and 

 winter, recognizing the periodical returns of heat and cold, 

 and (in some regions) of dry seasons and wet seasons, of 

 calm and storm, and so forth, without perceiving that the 

 sun runs through his changes of diurnal motion in the same 

 cyclic period. We can imagine that some few who might 

 notice the connection between the two orders of celestial 

 phenomena would be anxious to spread their faith in the 

 association among their less observant brethren. They 

 might maintain that observatories for watching the motions 

 of the sun would demonstrate either that their belief was 

 just or that it was not so, would in fact dispose finally of 

 the question. It is giving the most advantageous possible 

 position to those who now advocate the erection of solar 

 observatories for determining what connection, if any, may 

 exist between sun-spots and terrestrial phenomena, thus to 

 compare them to observers who had noted a relation which 

 unquestionably exists. But it is worthy of notice that if 

 those whom I have imagined thus urging the erection of an 

 observatory for solving the question whether the sun rules 

 the seasons, and to some degree regulates the recurrence 

 of dry or rainy, and of calm or stormy weather, had pro- 

 mised results of material value from their observations, they 

 would have promised more than they could possibly have 

 performed. Even in this most favourable case, where the 

 sun is, beyond all question, the efficient ruling body, where 

 the nature of the cyclic change is most exactly determinable, 

 and where even the way in which the sun acts can be 

 exactly ascertained, no direct benefit accrues from the 

 knowledge. The exact determination of the sun's apparent 

 motions has its value, and this value is great, but it is most 

 certainly not derived from any power of predicting the re- 

 currence of those phenomena which nevertheless depend 

 directly on the sun's action. The farmer who in any 

 given year knows from the almanac the exact duration of 



