796 



SCIENCE. 



[N. S. Vol. XXI. No. 542. 



diminishes suddenly to below 50 per cent. 

 The temperature continues to rise through a 

 stratum sometimes 1,000 meters in tliickness, 

 and the humidity decreases to 10 per cent, or 

 20 per cent. Above this stratum the adiabatic 

 rate is again met with, but the humidity is 

 low. The northeast trade, with a velocity of 

 about sixteen miles an hour, prevails at sea 

 level. At greater altitudes the wind shifted 

 gradually through north to northwest, and in 

 two instances through east to southeast and 

 south. No southwest current (anti-trades) 

 was shown by the kites. The northwest or 

 southeast winds in the highest strata had a 

 velocity not over seven or nine miles an hour. 

 In the intermediate strata the velocity was 

 generally even lower (Nature, March 16, 1905, 

 467; Ciel et Terre, March 16, 1905, pp. 47-49). 



MOUNTAIN SICKNESS. 



In an account of ' Five Ascents to the Ob- 

 servatories of Mont Blanc' (Appalachia, Vol. 

 X., No. 4), Mr. A. L. Rotch describes his dif- 

 ferent experiences, and pays special attention 

 to the physiological effects of the high alti- 

 tudes. On the first ascent, at a height of 

 14,320 feet, where the night was spent, the 

 author suffered with this most distressing 

 malady, but was afforded some relief by 

 breathing oxygen. In the morning he was 

 well enough to aid in setting up the barom- 

 eters and to undertake preliminary spectro- 

 scopic observations. Another night, spent at 

 the Vallot cabin, 1,460 feet below the summit, 

 was also made unpleasant by a repetition of 

 the discomforts of mountain sickness. On a 

 second expedition oxygen failed to give any 

 relief, but some alleviation was obtained by 

 the use of phenacetine. The third ascent was 

 marked by suffocation and dizziness during 

 the night spent at the Grands Mulcts shelter, 

 the pulse rising to 100, the altitude being com- 

 paratively low. Mr. Rotch attributes these 

 symptoms to a large quantity of quinine which 

 he had taken before starting. On the further 

 climb, great difficulty was experienced in walk- 

 ing, and there was hardly strength enough, at 

 the Vallot Observatory, to gather up the sheets 

 of the recording instruments. A fourth ascent 



was accomplished without difficulty, the author 

 being ' in prime condition ' on the summit. 



MONTHLY WEATHER REVIEW. 



The November number of the Monthly 

 Weather Review (dated January 31, 1905) 

 contains the following articles of general sci- 

 entific interest : ' Airy's Theory of the Rain- 

 bow,' by Rev. D. Hammer, S.J. ; ' Radiation in 

 the Solar System,' being an address delivered 

 before the British Association by Professor J. 

 H. Poynting; 'A Simple, Effective and Inex- 

 pensive Lightning Recorder,' by H. F. Alcia- 

 tore ; ' An Honest Long-range Forecaster,' 

 ' Meteorological Course at Williams College,' 

 ' Meteorology in New South Wales,' ' Deflec- 

 tion of Thunderstorms with the Tides,' ' A 

 Proposed International Contest of Weather 

 Forecasters.' 



FLOODS IN the SAHARA. 



Occasional sudden downpours of rain, some- 

 what similar in character to our western cloud- 

 bursts, occur in the mountains of the Saharan 

 region, causing floods, and even loss of life. 

 On the evening of April 12,. 1899, near Ber- 

 rian, 300 miles south of the city of Algiers, a 

 flood of this character swept down the usually 

 dry bed of a wady, and caused the death, by 

 drowning, of some French soldiers who were 

 encamped in the bed. A recent case of the 

 same kind is reported in the Bulletin of the 

 Comite de I'Afrique, No. 11, 1904. On Oc- 

 tober 21 the village of Ai'n Sefra, in southern 

 Algeria, on the edge of the Sahara, was over- 

 whelmed by floods which suddenly rushed 

 down two wadys. The floods were due to very 

 heavy rains which had fallen on a neighboring 

 mountain range. Ten Europeans and fifteen 

 natives were drowned. The flood is reported 

 to have subsided about fifteen minutes after 

 reaching the town. 



THE GUINEA CURRENT. 



In 1895 there was published by the Meteor- 

 ological Institute of the Netherlands a report 

 entitled ' De Guinea en Equatoriaal Stroo- 

 men,' dealing with the currents, temperature, 

 winds, specific gravity of ocean water, pres- 

 sure, freq^iency of rainy days, etc., of the re- 



