proceedings: biological society 239 



(3) Nernst-lamp spectrum observed through a \ cm. quartz plate; 



(4) Ditto corrected to allow for the reflections from the surfaces of the 

 quartz plate; nearly equivalent to ordinates of the energy curve of a 

 monochromatic line with the energy scattered to the long-wave side; 



(5) Total field light which would be expected in the spectrum of a 

 Nernst lamp when the intensity of the latter is 100,000 at 1.8m (see 

 line 7); (6) Computed relative intensities in black-body spectrum of 

 a body at 2200°K radiating to one at 300°K; (7) Corrected observed 

 intensities of Nernst-lamp spectrum approximating the conditions of 

 line 6 but differing for wave-lengths greater than 12/z because of the 

 increasing absorption of energy in the rock-salt plate closing the vacuum 

 bolometer case and in the prism, and the decreasing absorption by the 

 lamp-blacked surface of the bolometer strip. The intensity of the 

 scattered energy is really very small in any given region although the 

 total amount lost from any region amounts to about 3 per cent of the 

 true intensity of the region. At an angle of 10 minutes from the di- 

 rection in which the beam is normally reflected the intensity of the 

 scattered energy is only about 0.2 of 1 per cent of that of the main 

 image. It will be noted in the table that at 17.5/x the field light is 

 over five times the true-energy in the lamp spectrum. From a badly 

 tarnished mirror the increase in scattered light is relatively greater 

 for greater deviations from the main image. (This paper will probably 

 appear in the Astrophysical Journal.) 



Discussion. Mr. C. G. Abbot commented on the large amount of 

 work necessary to obtain the results presented. 



Informal communications. Mr. C. G. Abbot spoke of difficulties in 

 producing satisfactory damping in galvanometers, and Mr. W. P. 

 White mentioned a variation in damping with the magnitude of the 

 deflection, that would seem to be clue to the damping effect of the air 

 in the clearance space between the armature and the pole pieces. 



Donald H. Sw'eet, Secretary. 



THE BIOLOGICAL SOCIETY OF WASHINGTON 



The 567th regular meeting of the Society was held in the Assembly 

 Hall of the Cosmos Club, Saturday March 10, 1917; called to order by 

 President Hay at 8 p.m.; 45 persons in attendance. 



On recommendation of the Council, Mrs. L. O. Howard and Dr. 

 Martha Brewer Lyon were elected to active membership. 



Under the heading book notices, brief notes, etc., Dr. H. M. Smith 

 exhibited a manuscript and hand-illustrated book dealing with beetles. 

 It was about 60 years old. Dr. Smith presented it to Dr. L. O. Howard. 

 Prof. W. P. Hay presented some notes on the flying squirrels of this 

 vicinity with observations on their habits and behavior as pets. Dr. 

 H. E. Ames called attention to a newspaper clipping recording the 

 flight of two tagged ducks a distance of 2000 miles in about 60 hours. 

 He sought verification of the statement. 



