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RECENT PROGRESS IN GEODESY. 
BY 
John Fillmore Hayford. 
[Read before the Society February 3, 1900.] 
This report is not based upon a complete examination of 
the recent literature of geodesy. The writer has been too 
busy to devote much time to the special research necessary 
to justify any claim to completeness. His regular duties 
have, however, kept him in touch with recent operations in 
geodesy, much more closely in touch, however, with opera¬ 
tions in the United States than with those of Europe. The 
sketches of recent progress in each of several sciences called 
for by the rules of the Society are, as I conceive, to be writ¬ 
ten primarily, not for those well versed in that particular 
science, but for the general information of others working on 
other lines. To this end a bird’s-eye view of the present 
state of the particular science, together with a statement of 
the more important and interesting recent developments, 
will serve better than a detailed catalogue of the separate 
steps which make up recent progress. 
By studying the recent reports of the International Geo¬ 
detic Association and the geodetic reports from various coun¬ 
tries, one is gradually convinced that there is well-sustained 
activity in geodetic operations in many countries, that geo¬ 
detic facts are being steadily accumulated, and that steady 
progress is being made in improving methods and instru¬ 
ments. Having realized this, one naturally looks for pub¬ 
lished collections of results, and for some reasonably com¬ 
plete' and well-digested scientific papers showing the relation 
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1—Bull. Phil. Soc. Wash., Vol. 14. 
