November 1, 1895. ] 



SCIENCE. 



517 



for the cotton interests, the display of frost 

 and cold wave signals, the distribution of 

 meteorological information in the interests 

 of agriculture and commerce and the taking 

 of such meteorological observations as may 

 be necessary to establish and record the cli- 

 matic conditions of the United States, or as 

 are essential for the proper execvition of the 

 foregoing duties." 



It will be seen that the main object for the 

 existence and continuation of this Bureau 

 is to give warning of the approach of 

 storms, and therefore that the proper line 

 of investigation should be for the purpose 

 of determining the true philosophy of 

 storms. The goal to be striven for is the 

 improvement of weather forecasts, and 

 surely one of the prerequisites to determine 

 coming events is a thorough knowledge of 

 existing conditions. 



To those who have read every important 

 treatise on meteorology, and who have 

 studied every text-book on the subject, it is 

 painfully patent that we are extremely 

 ignorant of the mechanism of storms; of the 

 operations of those vast and subtle forces 

 in free air which give inception to the 

 storm and which supply the energy neces- 

 sary to accelerate cyclonic action when 

 formed, or to disperse the same when 

 once fully in operation. We know that 

 great atmospheric swirls in the shape of 

 high and low pressure areas alternately 

 drift across the country at intervals of two 

 or three days; that the atmosphere flows 

 spirally into the cyclonic or low-pressure 

 system and outward from the anti-cyclonic 

 or high-pressure sj^stem, that the in-drawn 

 east and south winds on the front of the 

 storm are warm, and that the inwardly- 

 flowing north and west winds are cold. 



The theories of Eedfield, Espy, Loomis, 

 Ferrel and others, teach that our great 

 storms are composed of immense masses of 

 air gyrating about a vertical or nearly ver- 

 tical axis, drifting eastward and at the same 

 time drawing in warm easterly currents at 



the front and cold westerly currents at 

 the rear; that the commingling of these two 

 as they rise to greater and greater eleva- 

 tions, near the regions of the cyclonic center, 

 throws down volumes of rain or snow; 

 that as precipitation occurs with the 

 ascending currents, the heat of condensa- 

 tion energizes the cj'clonic circulation ; that 

 the air at the center of the storm is rela- 

 tively warm, is rarefied by centrifugal force 

 and by reason of less density, rises to a 

 great elevation, and in the upper regions of 

 the atmosphere flows away laterally to as- 

 sist in building up high-pressure areas on 

 either side. 



The high and low-pressure areas are 

 supposed to be carried eastward by the 

 general easterly drift of the atmosphere 

 in the middle latitudes, somewhat as ed- 

 dies are carried along by water in a running 

 stream. 



But, unfortunately for the complete accu- 

 racy of these theories, the forecaster often 

 finds heavy down-pours of rain without 

 any cyclonic circulation, and no convec- 

 tional system in operation ; again over im- 

 mense areas of country, especially in the 

 Eocky Mountain region, for many months 

 in the year condensation occurs not at all 

 in the warmer easterlj' currents flowing into 

 the storm center, bvit almost exclusively in 

 the westerly portion of the storm area, 

 where the cold north and west winds are 

 flowing in. 



Again, many investigators to-day have 

 good reason to doubt that the center of the 

 storm is warm to any great elevation or 

 that cyclonic circulation obtains to the top 

 of the air. 



In outlining, in a rough and general way, 

 the line of investigation which in my judg- 

 ment promises to give the most prolific re- 

 sults, not only to the cause of meteorological 

 science, but to the making of more accurate 

 forecasts for the benefit of agriculture and 

 commerce, I will say that we have been for 



