76 



SCIENCE. 



[N. S. Vol. XXI. No. 524. 



bad, the farmer is greatly restricted in the 

 times when he can go to market. If high 

 prices coincide with a period of wet weather 

 and deep mud, the farmer may lose his oppor- 

 tunity of getting his crops to market. In 

 France, cold or stormy days are often used for 

 hauling to market, but American farmers 

 usually have to use for hauling the days which 

 are the best for work on the farm. Railroad 

 receipts often suffer a serious falling off when 

 the weather is severe, and when the country 

 roads are in such condition that farmers can 

 not haul their produce to the train. 



MONTHLY WEATHER REVIEW. 



The Monthly Weather Review for Septem- 

 ber, 1904 (dated November 19), contains the 

 following articles of general interest: H. 

 Elias, ' A New Theory of Fog Formation ' 

 (translated from the German) ; J. H. Spencer, 

 ' Three Notable Meteorological Exhibits at the 

 World's Fair ' (the U. S. Weather Bureau, the 

 German and the Philippine Weather Bureau 

 exhibits); and the following notes: 'Meteor- 

 ology in Roumania ' ; ' Observations for Twelve 

 Months in Lassa ' (data obtained by M. Tys- 

 bikov, a Russian, who resided in Lassa from 

 August 15, 1900, to August 22, 1901); 'Ob- 

 servations at the Franco-Scandinavian Sta- 

 tion for Aerial Soundings ' (from Comptes 

 Rendus) ; ' Wind Velocity and Ocean Waves ' 

 (from a recent paper by Cornish). 



NO SECULAR CHANfiE OF CLIMATE IN TRIPOLI. 



Vicomte de Matiiusieulx, in an account of 

 his expedition to Tripoli (Bull. Amer. Geogr. 

 Soc, December, 1904), states it as his opinion 

 that there is no reason for supposing any 

 secular change of climate to have occurred in 

 that region, although others have taken the 

 opposite view. The Latin texts and monu- 

 ments seem, to this writer, to establish the 

 fact that so far as the atmosphere and soil 

 are concerned, everything is just as it was in 

 antiquity. The present condition of the 

 country is ascribed to the idleness of the 

 Arabs, who have allowed innumerable wells 

 to become choked and the vegetation to perish. 

 " In a country so little favored by nature, the 

 first requisite is a diligent and hard-working 



population. The Romans took several cen- 

 turies to make the land productive by dam- 

 ming the ravines and sinking wells in the 

 wady beds." 



climatic change in the lake chad region. 



The evidence from the region between the 

 Ubangi River and Lake Chad, studied by M. 

 Aug. Chevalier in 1902-3, is, however, be- 

 lieved to point towards a progressive desicca- 

 tion there (La Geographie, May, 1904). M. 

 Chevalier thinks it probable that a great river 

 once flowed north across the Sahara to the 

 Mediterranean, and that Lake Chad was mere- 

 ly a back water. Vegetable and animal re- 

 mains indicate an invasion of the Sudan by 

 the Saharan climate, and Neolithic relics indi- 

 cate the former presence of prosperous com- 

 munities. The change is not a regularly 

 progressive one, for Lake Chad sometimes 

 spreads beyond its usual bed as a result of 

 several years of heavy rainfall. Since 1897 

 the waters have continued to fall. After a 

 drought in 1902, Lake Fittri dried up in the 

 following year, and hippopotami which inhab- 

 ited it went elsewhere. 



kite meteorology over lake CONSTANCE. 



Dr. Hergesell has contributed to a recent 

 number of the Beitrdge zur PhysiJc der freien 

 Atmosphdre an account of the observations 

 made by him with kites on the Lake of Con- 

 stance, the flights being made from a motor- 

 boat, loaned by Count Zeppelin, during the 

 years 1900, 1902 and 1903. The observations 

 show that inversions of temperature and of 

 humidity frequently occur in the free air 

 which are not exhibited by the observations 

 made at mountain observatories. 



R. DeC. Ward. 



the first observations with 'ballons-soxdes' 

 in america. 

 As is known to many readers of Science, 

 there have been despatched in Europe fre- 

 quently during the past ten years hallons- 

 sondes, or small balloons carrying only instru- 

 ments that record automatically the tempera- 

 ture and pressure of the air, thus enabling the 



