794 



SCIENCE. 



[N. S, Vol. VII. No. 180. 



lights for the purpose of disseminating 

 weather forecasts. The search light of the 

 TJ. S. S. Maine, which was at the time 

 nearly completed, was, in February, 1895, 

 loaned by the N'avy Department to the 

 Weather Bureau for temporary use in 

 Chicago, in experiments designed to test the 

 efficiency of such a means of distributing 

 warnings of coming important weather 

 changes. The light, which had a lens 30 

 inches in diameter and whose candle power 

 was estimated at about 100,000, was erected 

 on the roof of the Auditorium Building, in 

 Chicago, at an elevation of 270 feet above 

 the level of the street. It was used but 

 once, on February 28, 1895, in giving a 

 warning of a coming cold wave, the light 

 being slowly revolved at the rate of one 

 revolution in five minutes. The night was 

 dark and cloudy, and the signal was seen 

 at a distance of 20 miles. A number of 

 experimental trials were also made, and it 

 was concluded that search lights are not 

 useful for the purpose of disseminating fore- 

 casts except under the most favorable cir- 

 cumstances. The compiler of these Notes 

 recalls that a number of years ago a similar 

 attempt was made during one summer to 

 flash weather forecasts from the summit of 

 Mt. Washington, in New Hampshire 

 (6,279 feet) . This was a private enterprise, 

 in the nature of an advertisement, but was 

 fairly successful as far as the distribution of 

 the forecasts was concern.ed. 



CIVIL SERVICE EXAMINATIOKS FOE POSITIONS 

 IN THE WEATHEE BUEEAU. 



It is pleasant to learn, from a note by 

 Professor Abbe in the MontMy Weather Re- 

 view for February, something of the Civil 

 Service Examinations set for candidates 

 for positions in the Weather Bureau. 

 Since 1893 all the positions, except those 

 of Chief and Assistant Chief, have been in 

 the classified service, and therefore a special 

 system of examinations has been arranged. 



The examination for the position of Obser- 

 ver in the Weather Bureau embraces the fol- 

 lowing subjects, besides spelling, arithmetic, 

 etc., with the respective weights as given, 

 viz., practical questions in meteorology, 40 ; 

 an essay on a practical subject in meteor- 

 ology, 20 ; geography of the United States, 

 10, the total number of points being 100. 



FALSE DEW. 



Aitken's theory that much of what is 

 ordinarily called dew does not come from 

 the water vapor in the air, but from within 

 the plants on which moisture is seen, has 

 received further experimental confirmation 

 at the University of Nebraska, where Pro- 

 fessor C. E. Bessey has been carrying on 

 investigations along the lines suggested by 

 Aitken's own observations {Monthly Weather 

 Revieiu, March). These studies show that, 

 when the soil is moist and warm, the leaves 

 of plants exude water, which forms in drops 

 on the plants when evaporation from the 

 leaves is checked by the cooling and the 

 consequent increase in the humidity of the 

 air. In cases of unusually active plants, 

 drops may be forced out in dry, warm air. 

 These drops form what is known as ' false 

 dew,' and the process is known as ' gutta- 

 tion.' 



NOTES. 



Feom the Meteorologische Zeitsehrift for 

 April we learn that a bibliography of Italian 

 meteorology is being prepared by the libra- 

 rian of the Observatory of Moncalieri, near 

 Turin, the list to include all books, pam- 

 phlets and articles bearing on meteorology 

 which have been published in Italian. 



Among noteworthy recent articles is the 

 following : J. Hann : Ueber die Reduktion 

 kiirzerer Reihen von Niedersehlagsmessungen 

 auf die langjdhrige Reihe einer Naclibarstation. 

 Met. Zeitschr., Apr., 1898, 121-133. 



E. DeC. Ward. 

 Haevaed University. 



