400 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 11, NO, 16 



spot numbers direct for comparison with magnetic and electric variations, 

 it is found that a more satisfactory measure of solar radiations and emana- 

 tions affecting the Earth's magnetic and electric condition may be based 

 upon the monthly range of sun-spot frequency, or upon some quantity indica- 

 tive of the rate of change, or variability of sun-spottedness. 



(4) A discussion of the sun-spot data for the period of 44 years, 1876-1920, 

 confirms the existence of an annual periodicity in sun-spottedness, the mini- 

 mum occurring about the time (January) when the Earth is nearest the Sun, 

 and the maximum occuring on the average in July, when the Earth is farthest 

 away from the vSun ; the average difference between maximum and mimimum 

 is about 6 sun-spot numbers. There would thus be given additional support 

 to the view of planetary influence upon sun-spottedness. 



(5) The electric potential-gradient, on the average, for both hemispheres 

 shows a minimum value in July and a maximum in January; the annual 

 range is about 50 per cent. On the other hand, the Earth's magnetic energy, 

 as well as the strength of earth-currents, show on the average a higher value 

 during the summer months than during the winter months for the northern 

 hemisphere. 



The paper was discussed by Dr. Humphreys. 



A more complete summary will appear in the current volume of Terrestrial 

 Magnetism and Atmospheric Electricity. 



H. H. Kimball, Recording Secretary 



SCIENTIFIC NOTES AND NEWS 



Mr. Louis V. Dieter has resigned as bacteriologist of the Health De- 

 partment of the District of Columbia. He had been with the department 

 since 1909. 



Dr. Henry Gordon Gale, professor of physics at the University of Chi- 

 cago, has been made chairman of the Division of Physical Sciences of the 

 National Research Council, for the year ending June .30, 1922. 



Captain Anthony Francis Lucas, retired mining engineer, died at his 

 home at 2.300 Wyoming Avenue on September 2, 1921, in his sixty-sixth 

 year. Captain Lucas was of Montenegrin origin and was born at Trieste 

 on September 9, 185.3. He was for a number of years an officer in the Aus- 

 trian navy. He took an active part in the development of the oil and gas 

 fields of the Gulf Coastal Plain, and was particularly interested in the geo- 

 logical problems of the origin of petroleum and the origin of the salt domes of 

 Louisiana and Texas. He was a member of the Geological vSociety and the 

 Society of Engineers. 



Mr. J. E. Noble has been appointed bacteriologist of the Health Depart- 

 ment of the District of Columbia. 



Dr. George B. Roth, pharmacologist with the Hygienic Laboratory of 

 the U. S. Public Health Service, resigned in September to accept a teaching 

 and research professorship at Western Reserve University, Cleveland, Ohio. 



Mr. Charles K. Wead, for over twenty years an examiner in the U. vS. 

 Patent Office in the Class of Music, has resigned, and will reside at Ann 

 Arbor, Michigan. 



Professor Charles E. Weaver, non-resident member of the Academy, 

 has returned to the University of Washington at vSeattle to resume his work 

 as professor of paleontology, after a leave of absence of three years in Central 

 and vSouth America as geologist for the Standard Oil Company. 



