164 METHODS OF FOKECASTING THE WEATHEE. 



This heating- intlucnco of the sun, as also its modilications by cloudi- 

 ness, by the wind, by the change from day to night or from winter to 

 summer, and by the properties of the earth's surface, which, consist- 

 ing as it does of water and of land either covered with vegetation or 

 barren and bald, has varying capacities for absorbing the sun's heat — 

 this influence of the heat of the sun has been established with the most 

 absolute certainty l)y the most exact observations. It has been demon- 

 strated to be so much more important than any other cause, if any 

 such exists, that up to the present time it has not been possible to 

 recognize any other cause with certainty, in spite of the fact that the 

 professional meteorologists, and singularly enough they only, have 

 instituted extensive and most thoroughly exact investigations in order 

 to discover such other influences, in case there are any, and to deter- 

 mine their value. And what has been the result of these extraordi- 

 naril}' lal)orious and wearisome investigations!' Before I answer this 

 question I must call your attention to the fact that not one of the rep- 

 resentatives of the theory of the influence of the moon, or of any other 

 cosmical influence, has undertaken to give an unobjectionable rigor- 

 ous demonstration of such an influence. These gentlemen content 

 themselves with the inventive method and appl}^ it in a very singular 

 manner. They make their predictions for certain days and always 

 call attention to the cases when they are successful, but never trouble 

 themselves al>out the failures. Now, 1 beg you to observe that in 

 every game of chance where there are but two alternatives there nuist 

 occur fift}^ verifications out of every one hundred guesses, when a 

 great numl)er of guesses are made and it is all pure chance. The 

 time at which the game of chance is played, or the time when the 

 guess is made, is absolutely' without any influence whatever upon the 

 result. So, also, the drawing out of an even or uneven number of 

 balls could have no influence upon the weather, even if it should occur 

 to some one always to predict fine weather when he drew an even' 

 numl)er and bad weather when he drew an uneven one. If, there- 

 fore, one should make use of the above-mentioned inventive methods, 

 he should carefuU}- record all the cases — the failures as well as the 

 verifications. And then, even if every second case is a success — that 

 is to say, even if he obtains 50 per cent of verifications — ho will know 

 that the theorem or assumption made use of as the basis of the pre- 

 dictions really has no causal connection with the weather. Only when 

 more than 50 per cent of verifications are attained can the argument 

 favor the assumption, and so much the more in proportion as the 

 verifications exceed 50 per cent. 



This exact method, the only one for testing their hypotheses as to 

 the cosmical influences on the weather, is the one that has never been 

 applied; in fact, it has often been distinctl}^ rejected by those who 

 maintain the existence of these influences; and yet those who make 



