METHODS OF FORECASTING THE WEATHER. 157 



moon with respect to the earth and the sun, with the assistance of 

 the laws of attraction — without any strict investio-ition as to how far 

 these can possibly be of influence — the}" compute the attraction exer- 

 cised by the moon in its separate positions, and say on such and such 

 a day the influence of the moon must have produced such and such a 

 result on the weather. The contirmation of these predictions by 

 the observations should then only show the accuracy of their assump- 

 tions and computations. The number of tliese modern moon pi'oph- 

 ets is at present larg-e. Many of them take into consideration the 

 planets in addition to the moon. The names of the most prominent 

 advocates of these moon theories are known to you. They arc as fol- 

 lows: Falb, Ledochowski, Gladbach, Demtschinski, Garigou-Lagrange, 

 A. Poincare — not the celebrated mathematician — and Digby. 



It would be quite erroneous if this method of investigation into the 

 causes of the weather were regarded as incorrect and improper. By 

 this presentation of the subject I wish only to show that the modern 

 moon prophets — and pro])aljly also the older ones — have not intro- 

 duced stricth" inductive empirical methods into their belief in the 

 moon, but that this belief was there from the first and that they have 

 made use of the discovery method for its confirmation, since it is on 

 the basis of the moon theory, or, if you prefer, of aprioristic consid- 

 erations as to the influence of the moon, that they make their weather 

 predictions, and then from the agreement betw een these they endeavor 

 to deduce the correctness of their assumptions. Against this method 

 as such there is nothing to be said, ])ut it demands the most conscien- 

 tious, straightforward, logical, and accurate determination of the con- 

 sec^uent weather if we wish I)}' this method to arrive at a confirmation 

 or refutation of the propositions advanced as to the influence of the 

 moon. How this is to be managed we have still to learn; meanwhile 

 it is at present only necessary, in this enumeration of the various 

 methods for predicting the Aveather, to include that one which repre- 

 sents the influence of the moon. 



As soon as men began to obserAC the barometer attentively, the}^ 

 began gradually to recognize that the rising and falling of the barom- 

 eter had an evident connection wdtli the weather. It was the celebrated 

 burgomaster, Otto von Guericke, of Magdeburg, Avho first used the 

 barometer as a " weather glass." He applied, even then, to his water 

 barometer the ''weather scale" which is at present in such general 

 use, on which the highest reading occurring at any place is designated 

 as "fine weather," the lowest reading as "rain and wind," etc. 

 The barometer as a weather glass has taken its course throughout the 

 world, and is to-day used almost universally. After tiie introduction 

 of the aneroid barometer th(^ " weather scale" was also aflixed to that, 

 and whoever ])ui'chases such an instrument paj^s particular attention to 



