cxxii Trans. Acad. Sci. of St. Louis. 



Don Alfredo Chavero of Mexico, an Honorary Member, 

 and of Dr. E. C. Chase, an active member. 



Mr. Edward H. Bowie, in charge of the Weather Bureau 

 in this city read a paper on " Predetermination of Paths of 

 Centers of Cyclonic Areas, " illustrated with lantern slides. 



After a short introductory sketch of the pioneers of me- 

 teorology in the West whose works largely influenced the 

 establishment of the Signal Service and later of the 

 Weather Bureau, the speaker reviewed the writings of 

 meteorologists, treating of the formation and structure of the 

 atmospheric whirls or eddies, called cyclones. He discussed 

 the work of Franklin, Redfield, Espy, Tracy, Coffin, Loomis, 

 Ferrel and Bigelow, which resulted in establishinor the follow- 

 ing facts concerning the formation and structure of cyclones : — 



1. That extra tropical storms are not local in their origin, 

 but have their source in the heat that is transported from the 

 tropics through horizontal currents near the earth's surface. 



2. The formation of tropical cyclones or hurricanes is fully 

 accounted for by the vertical convectional theory. 



3. The aqueous vapor condensed into water and the latent 

 heat liberated is an effect of, but not necessarily the cause 

 of the formation of a cj'^clone, being, however, a great factor 

 in intensifying the storm. 



4. Observations do not show that abnormal heat in a 

 locality necessarily give birth to cyclones. 



5. Cyclones are whirling masses of atmosphere, whose 

 horizontal diameter may be more than four or five miles, ex- 

 cept in the cases of tropical storms where it is greater. 



The speaker then discussed the forces that propel a storm 

 after it is established. After reviewing the work of such 

 eminent men as Loomis, Abercromby, Ley, Eliot, Rosser, 

 Abbe, Bigelow and Garriott, he discussed at length a method 

 for determining the direction of a storm and its rate of pro- 

 gress as worked out by himself. His method is based upon 

 tiie assumption that "storms are eddies carried along by 

 the general eastward drift, but having their direction and 

 rate of progression modified by the flow of air from adja- 

 cent areas of high pressure." 



