376 PHILOSOPHICAL SOCIETY OF WASHINGTON. 
Past Presidents. 
M. Baker. 
F. H. Bigelow. 
F. W. Clarke. 
W. H. Ball. 
W. Harkness. 
S. Newcomb. 
G. M. Sternberg. 
0. H. Tittmann. 
President Walcott then took the chair. 
The Chairman raised the question whether this meeting 
should be treated as the first meeting of the new Society or as 
one of the old series. After some discussion he stated that by 
unanimous consent the organization was to be considered as 
continuous. 
Mr. G. M. Sternberg then read a paper on The transmission 
of yellow fever by mosquitoes. Researches made by Dr. Reid 
under direction of the Surgeon General have established the fact 
that the disease is not communicated by bedding, etc., used by 
a patient, nor through the air; the injection of blood from a 
yellow fever patient into the blood of a healthy person will com¬ 
municate it; but the usual means of transmission is through a 
mosquito, in whose body it requires 12 days for the germ to de¬ 
velop. This theory explains many long-known and puzzling 
facts, and indicates that the disease may be stamped out by pre¬ 
venting the access of mosquitoes to patients having the disease. 
[Not published.] 
The paper was discussed by Messrs. Bauer, Bigelow, Gore, 
Hayford, and Marvin. 
Mr. J. W. Froley read a paper entitled Mathematical discus¬ 
sion of appliances for describing oval and circular arcs of very 
large radius. The principal one of these was based on the fact 
that under special conditions the elastic curve produced by par¬ 
allel forces becomes a circular arc. [Not published.] 
The paper was discussed by Messrs. Baker, Hayford, Radel- 
finger, and Wead. 
538th Meeting. October 12, 1901. 
Past President Baker in the chair. 
Twenty-six persons present. 
Mr. Green spoke informally of the creeping on its base of 
