DEPARTMENT OF BOTANICAL RESEARCH. 69 



series of lath shelters designed solely for the culture of plants has been 

 extended. 



Six balances, of the form known as silk scales, which had been recom- 

 mended after trial by the Director of the Nutrition Laboratory, were acquired 

 for use in the work on the water-balance of succulents. 



Local transportation and delivery service having become a pressing matter, 

 a second-hand gasoline runabout was purchased in New York and shipped to 

 the Laboratory at the beginning of the year. The use of this machine during 

 the busier seasons amounts to about 1,000 miles per month. 



The wooden sailboat (by the aid of which three years' work was carried 

 out on Salton Lake) having become unseaworthy, a motorboat designed by 

 Mr. G. Sykes and built under his supervision in the shop of the Department 

 was finished early in June and is now in commission. The hull is of steel, 

 fitted with water-tight compartments, and supplies of gasoline and oil may be 

 carried sufficient for the circumnavigation of the lake. This boat has shown 

 good behavior in rough weather and gives an average speed of 6 miles per 

 hour. In intervals between expeditions it is kept at the dock of the evapora- 

 tion station of the U. S. Weather Bureau at Salton trestle. 



The shop equipment has been brought to a high state of efficiency by the 

 purchase of a number of tools, and by the careful setting and adjustment of 

 the precision tools. 



The additions to the equipment of the laboratories include thermographs, a 

 new model solar radio-integrator, recording rain-gages, condensers, and many 

 minor pieces of apparatus. A small model of an ice-machine (in which 

 evaporation in a vacuum is reinforced by the absorbent action of sulphuric 

 acid) has been found to be very efficient in cooling water for drinking and 

 for use in the photographic dark-room at air-temperatures as high as 110° F. 



THE STAFF. 



Dr. Forrest Shreve spent the latter half of the year in Jamaica in the 

 completion of some habitat studies and experimentation in transpiration 

 begun in 1905. 



Dr. J. E. Kirkwood, who was in residence at the Desert Laboratory from 

 November, 1908, until July, 1909, in pursuance of his investigations on 

 guayule. Dr. Kirkwood has since accepted the appointment of assistant 

 professor of botany and forestry in the University of Montana. 



Dr. B. E. Livingston, who has been a member of the staff at the Desert 

 Laboratory since 1906, has accepted the appointment of professor of plant 

 physiology in Johns Hopkins University, beginning his new duties October i, 

 1909. Dr. Livingston retains his residence at Tucson and expects to spend 

 a few months in 1910 in continuation of his researches upon evaporimetry, 

 soil-moisture, and transpiration. An assistant will care for some of his 

 experimental work in the interim. 



