RECENT PROGRESS IN GEODESY. 
BY 
John Fillmore Hayford. 
[Read before the Society February 16, 1901.] 
So much has been published during the past year in regard 
to recent events in the world of geodesy that there is appar¬ 
ently little to be said upon this occasion ; but a bird’s-eye or 
general view of a subject has its own special interest and 
value, even to those who are familiar with the details. 
It is not necessary to review the recent progress in geodesy 
in foreign countries, since such a review was presented in 
January before the Society in the form of a report upon the 
International Geodetic Association Conference of 1900 by 
Mr. Isaac Winston, the delegate on the part of the United 
States to that conference, and this report is in print.* 
The principal geodetic enterprise now on foot in the United 
States is the measurement of a great arc along the ninety- 
eighth meridian from the Rio Grande to the Canadian border. 
Work upon this arc was commenced in 1896. The present 
state of the undertaking is that the reconnaissance is com¬ 
plete from northern Nebraska to the Rio Grande; that the 
triangulation—that is, the measurement of the horizontal 
and vertical angles—is complete from latitude 42J degrees, 
in northern Nebraska, to latitude 38 J degrees, in southern 
Kansas, a distance of about 300 miles along the meridian. 
Nine bases have been measured along this arc in addition to 
*See Science, January 25, 1901, pp. 129-133. A more complete report 
upon the conference is published in Revue Generate des Sciences, No¬ 
vember 15, 1900, pp. 1175-1183; November 30,1900, pp. 1224-1233. 
20-Bull. Phil. Soc., Wash., Vol. 14. 
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