August 17, 1900.] 



SCIENCE. 



269 



to hold a winter meeting at such time and 

 place as the Sectional Committee should de- 



Feank Eussell, 



Secretary. 

 Haevaed Univbesity. 



SCIENTIFIC BOOKS. 

 Etude sur la grSle. DSfenae des recoltes par le 



iir du canon. By V. Veemorel. Librairie 



du Progres Agricole et Viticole ; Villefranche. 



July, 1900. 



In this pamphlet of 77 pages the well-known 

 viticultural expert and director of the station 

 at Villefranche gives an account of the latest 

 (up to July 1st) phase of the subject of Wetter- 

 schiessen — the protection of crops from hail by 

 means of the vertical firing of specially con- 

 structed cannon at the threatening clouds. 

 Chapter 1 gives a risume of the various theories 

 of hail-formation, affording striking proof of 

 the uncertainty still existing in this regard, and 

 especially as to the part played by atmospheric 

 electricity in the most damaging hailstorms, 

 viz, those of summer. There follows a brief 

 discussion of the possible explanations of the 

 action of the vertical projection of the annular 

 whirl, which seems to be essential to the produc- 

 tion of the effect, and e. g. , tears a paper target 

 placed 100 meters from the gun, and according 

 to trigonometric measurements may reach a 

 height of over two kilometers. The claim made, 

 and sustained by an overwhelming number of 

 observations, is that the commotion caused by 

 these whirls in the hail-clouds, if produced in 

 time, will cause rain to fall in place of hail. 



Chapter 2 gives abstracts of the reports made 

 to the congress of Italian hail-protection syndi- 

 cates held at Casale Monteferrato in November, 

 1899, which was attended by three delegates 

 from Prance, the author among the number. 

 The reports are from the provinces of Vicenza, 

 Treviso, Verona, Padua, Udine, Pavia, Ber- 

 gamo, Alexandria and Novara. From all of 

 these regions the reports are very encouraging, 

 in part enthusiastic. The Bergamo reporter 

 sums up by saying that ' ' those who have done 

 the shooting are desirous of continuing it ; 

 those outside the defended area regret not hav- 

 ing done it. The results obtained this (last) 



season could not be more encouraging, and will 

 enable us to complete the means of defense." 

 This appears to be substantially the consensus 

 of opinion of those attending the congress. 



Chapter 3 gives the details of the construction 

 and handling of the cannon, which does not 

 differ materially from the original prescriptions 

 of Stiger, except in making the gun breech- 

 loading. 



Chapter 4 gives details of the desirable or- 

 ganization of the shooting stations, as now 

 established in the Beaujolais, Rhone Valley. 

 Isolated guns are of little value unless placed 

 on high points. Each gun ban defend 25 hec- 

 tares (62 acres) ; rapid and continuous firing is 

 especially important at the first approach of the 

 cloud. A code of signals is provided to insure 

 concerted and prompt action. The government 

 supplies powder for the purpose at reduced 

 rates. The expense of establishing a station is 

 placed at 11 francs ($2. 15) per hectare, or a little 

 less than $1 per acre ; current annual expense, 

 about 65 cents per acre, estimating that 500 

 shots may have to be fired. 



Among the striking points noted is that from 

 2000 stations last year, fifteen thousand are in 

 operation in Italy this year. Moreover, the in- 

 surance companies heve reduced the premiums 

 33 per cent, for the areas provided with shoot- 

 ing stations. 



Is it not about time that some experiments 

 in the same line were set on foot in our thunder- 

 storm-ridden Middle "West ? If, as some allege, 

 this is merely a passing popular delusion, it is a 

 remarkably persistent one, backed by very 

 heavy pecuniary investments, and not defi- 

 nitely assailable on scientific grounds. 



E. W. HiLGAED. 



A Brief Guide to the Commoner Butterflies of the 



Northern United States and Canada. By 



Samuel Hubbaed Scuddee. New York, 



Henry Holt & Co. 1899. Pp. xi + 210, 22 



plates of wood-cuts, 10 cuts in text. 



This book is a reprint of the first edition of 



the work, published by the same house in 1893, 



and so far as the reviewer is able to ascertain, 



is not different in any respect from the first 



edition, save in the addition of the plates, 



which were taken for the most part from the 



