24 REPORT OF NATIONAL MUSEUM, 1921. 
the library of her brother, the late Dr. Joseph Paxson Iddings, com- 
prising upward of 1,000 books and pamphlets, chiefly on geological 
subjects. Doctor Iddings, as is well known, was one of America’s 
leading petrologists, and his 40 years’ accumulation of author’s ex- 
cerpts in this branch of science was unusually large. 
PHOTOGRAPHIC LABORATORY. 
In illustrating Museum objects, largely for reproduction in the 
publications and in copying plans, diagrams, etc., required in con- - 
nection with the work of the Museum, there were made in the photo- 
graphic laboratory during the year 1,954 negatives, 11,267 black and 
white prints, 42 bromide enlargements, 162 panoramas, and 144 lan- 
tern slides, besides developing 467 field negatives and mounting 
1,008 prints. A number of improvements in the apparatus and 
equipment make it much easier to handle the work in the laboratory. 
MEETINGS AND CONGRESSES. 
As customary the National Academy of Sciences held its annual 
meeting in the Natural History Building of the Museum on April 
25, 26, and 27, 1921, using the auditorium for the scientific sessions, 
open to the public, on the afternoon and evening of the 25th, and 
on the morning and afternoon of the 26th; while the adjoining 
committee room, No. 42-48, was used for the business meetings ex- 
tending through the forenoon of the 27th. 
The evening session was devoted to an address by His Serene High- 
ness Albert I, Prince of Monaco, Agassiz medalist, and was fol- 
lowed by a reception to the Prince in the halls assigned to the Na- 
tional Gallery of Art. Other speakers before the academy and their 
subjects included: Gilbert N. Lewis, “Ultimate rational units”; 
William Duane, “ The quantum law and the Doppler effect”; P. W. 
Bridgman, “ Preliminary measurements of the effect of high pres- 
sures on the thermal conductivities of liquids”; C. EK. Mendenhall 
and Max Mason, “ The stratification of suspended particles”; J. R. 
Carson, “ Radiation from transmission lines”; J. R. Carson and J. J. 
Gilbert, “Transmission characteristics of the submarine cable”; 
W. F. Durand, “Application of the principle of similitude to the 
hydraulic problem of the surge chamber”; E. H. Hall, (1) “ Theories 
of osmotic pressure,” and (2) “Comments on the Borelius space- 
lattice theory of the metallic state”; G. P. Merrill, “ Metamorphism 
in meteorites”; W. M. Davis, (1) “The Island of Tagula, New 
Guinea, its satellites and coral reefs,” and (2) “The shallow seas of 
Australasia ”; A. G. Webster, (1) “ On the radiation of energy from 
coils in wireless telegraphy,” (2) “On the vibration of gun barrels,” 
and (3) “On the problem of steering an automobile around a 
