798 



SCIENCE 



[N. S. Vol. XXXVI. No. 936 



complete between the months of May and Oc- 

 tober. 



This meteorograph on the summit ( elev. 

 3,292 meters) is flanked by two similar in- 

 struments, one on the west at Truckee (elev. 

 1,798 meters), thirty miles distant, and the 

 other on the east at Pallon (elev. 1,208 meters), 

 fifty miles distant, thus affording a base line 

 eighty miles long and an apex approximately 

 one mile high. Kite flights have been inaugu- 

 rated to determine the meteorological error of 

 the summit station. By means of this ver- 

 tical triangle of stations, data are now being 

 actively gathered on the changing phases of 

 passing storms, and their possible relation to 

 the weather of the valleys beneath. 



A station with instruments of great pre- 

 cision is being established on the university 

 campus. The study of the movements of air 

 currents will be made by pilot balloons, for 

 the plateau is too sparsely settled to permit 

 the use of ballons-sondes. A share will also 

 be taken in the international kite flights. 



In the realm of applied science, the fore- 

 casting of frost from mountain tops is one of 

 the two main problems through which it is 

 desired to make the observatory of practical 

 service. This problem is still in the stages of 

 data-gathering; however, some relationship is 

 evident between the passing of storms and the 

 occurrence of frost. 



This problem has given rise to two others: 

 the relation of topography to the occurrence 

 of frost, and a temperature survey of the 

 agricultural lands of the state of Nevada. 

 For the study of the first problem, two sta- 

 tions with delicate apparatus for detecting 

 minute changes in humidity, temperature and 

 air movements are under preparation to be 

 placed near the surface on typical slopes in 

 conjunction with a free air station at the 

 university. 



The temperature survey has now been in 

 progress for two seasons. The purpose of the 

 survey is the delimiting of large areas suit- 

 able for fruit raising under all forms of eco- 

 nomic frost prevention, and the further di- 

 vision of these areas into thermal belts ac- 

 cording to the following classification: 



(a) Belts where the minimum temperature 

 never falls below 28° F. and fruit raising 

 would be highly profitable. 



(h) Belts where the minimum temperature 

 is between 24° and 27° and frost can be com- 

 bated at a reasonable expense. 



(c) Belts where the temperature falls be- 

 tween 18° and 23° and fruit raising as an in- 

 dustry would not be profitable. 



In belts where temperatures of 17° or lower 

 are encountered fruit raising is not advisable. 



Eighteen stations equipped with thermo- 

 graphs and standard thermometers are now 

 being employed in the work. The number may 

 finally be increased to twenty-five. These 

 stations are distributed at strategic points 

 from the highest land under irrigation ca- 

 nals to the lowest parts of the valley. It is 

 planned to obtain continuous records at each 

 station for three years before removing the 

 station to a new point. The survey at pres- 

 ent covers the basin of the Truckee River, on 

 which is situated the metropolis of the state. 

 Owing to the hearty cooperation of ranchers, 

 who act as voluntary observers, the expense of 

 the maintenance of the survey is slight. 



In the spring of 1911, when frosts were 

 heavy and frequent, the observatory staff, in 

 conjunction with others, demonstrated the 

 feasibility of orchard heating even under 

 strenuous conditions, with the result that 

 where only one farm corporation was heating 

 its orchard that season, the present year be- 

 tween fifteen and twenty owners of fruit 

 trees were engaged in the work. To give the 

 orchardists assurance of support in their 

 effort, a night telephone service was main- 

 tained for emergency frost-warning and two 

 automatic frost alarms were installed. To 

 further aid the isolated orchardists in ma- 

 king their own forecasts of frost, an analysis 

 of the fluctuation of temperature under semi- 

 arid conditions is now being made. To this 

 will soon be added the determination of the 

 quantitative effect of cloudiness and wind on 

 the retardation of falling temperatures. 



The second problem to which special atten- 

 tion is being devoted is the influence of moun- 

 tains and forests on the conservation of snow. 



