REPORT OF THE SECRETARY. 13 
of the research parties who will from time to time desire to work 
there. 
The class of researches to be prosecuted at this exceptionably fa- 
vorable station are not only of great scientific interest, but are ex- 
pected also to prove of value in determining questions having a direct, 
practical influence on the preservation and progress of human life on 
our globe. 
INTERNATIONAL STANDARD PYRHELIOMETERS. 
A limited grant from the Hodgkins fund was approved in Feb- 
ruary, 1909, for the construction of several silver disk pyrheliometers. 
These instruments are to be placed in charge of scientific investi- 
gators in widely separated localities for the purpose of establishing 
an international scale for the comparison of observations on solar 
radiation. The varying results published by observers have made 
the need of international cooperation in this connection apparent, 
and the matter has received considerable attention at conferences of 
the Solar Union. 
These simple and comparatively inexpensive instruments are to be 
constructed after a design by Mr. Abbot. Similar pyrheliometers 
have been employed in the researches of the Astrophysical Observa- 
tory for several years and have proved entirely satisfactory. 
PUBLICATIONS UNDER THE HODGKINS FUND. 
Bibliography of aeronautical literature——An exhaustive bibliog- 
raphy of aeronautical literature, compiled by Mr. Paul Brockett, 
assistant librarian of the Smithsonian Institution, has been com- 
pleted to July 1, 1909, and is now in course of publication. This 
work contains references to about 13,500 published articles and is 
designed to render available the voluminous literature in all lan- 
guages, on aviation. 
Mechanics of the earth’s atmosphere.—In 1891 the Institution pub- 
lished a volume of translations of important foreign memoirs on the 
“ Mechanics of the earth’s atmosphere,” which was prepared by Prof. 
Cleveland Abbe. There was put to press during the past year a sec- 
ond collection of papers on this subject. 
SMITHSONIAN TABLE AT NAPLES ZOOLOGICAL STATION. 
The occupants of the Smithsonian table at Naples during the past 
year were Dr. C. A. Kofoid, of the University of California and the 
San Diego Marine Biological Station, and Dr. F. M. Guyer, of the 
University of Cincinnati. Dr. Kofoid is studying the question of 
sexual reproduction among Dinoflagellata and carrying on experi- 
mental work on autotomy in Ceratium, with reference to temperature 
and vertical distribution in the sea. Their investigations covered a 
period of seven months. 
