24 PHILOSOPHICAL SOCIETY OF WASHINGTON. 
collection of titles on astronomy, meteorology, and allied sciences, 
the expense to the office to be only his actual outlay for clerical 
assistance. Prof. Symons’ catalogue already represented many 
years of bibliographical research, and to it he now added many 
titles, securing the co-operation of European meteorologists by per- 
sonal visits and by correspondence, and including the more impor- 
tant English libraries. 
This catalogue was received late in 1883, about two years having 
been spent in its compilation; it consisted of about 18,000 titles, 
chiefly of separate works, and may be considered as the foundation 
of the present bibliography. No further work was done until 
March, 1884, when an effort to secure the services of Prof. Lancaster 
having failed, the librarian of the Signal office was assigned to the 
work of preparing the catalogue for publication. 
The original intention had been to extend Prof. Symons’ work 
only by the combination of titles from the Royal Society catalogue, 
including those in vols. vii and viii (1864-1873), selected but 
not yet copied by Prof. Abbe, the catalogue to be arranged by 
authors and to form only a first contribution to the general meteoro- 
logical bibliography desired. 
But the large amount of material on hand, and the conviction 
that some recent contributions to the subject, especially the Reper- 
torium der deutschen Meteorologie by Dr. Hellmann, should be in- 
cluded, and that the periodical literature previous to 1800 and 
subsequent to 1873 should be represented, led to the consideration 
of an enlargement in the scope of the work. It was foreseen that 
the necessary delay in securing an appropriation for publication 
would afford opportunity for still further extension, and it was 
decided March 15, 1884, to complete the compilation so far as 
possible without postponing publication for this purpose and to 
issue an approximately complete general bibliography, of such form 
as to serve as a basis for supplementary volumes. 
In pursuance of this plan, every effort has been made to secure 
contributions, especially by indexing periodicals, by examination of 
printed and manuscript catalogues and bibliographies, and by cor- 
respondence with meteorologists and librarians. 
The lacunz in periodical literature have been filled by indexing 
all periodicals available previous to 1800 and subsequent to 1873, 
and by the examination of all indexes, bibliographies, &ec., avail- 
able, such as Reuss, Young, Poggendorff, Kerl, Fortschritte der 
