Duplex measures, making the final contact.
"Contact" meant bringing the two aligned bars together so the ends were touching
. Fig. No. 7, Appendix No. 3, Report of Superintendent ... 1901, p. 244.
Image ID: theb1146, NOAA's Historic Coast & Geodetic Survey (C&GS) Collection
Photo Date: 1901
Category: Geodesy/Base Line/
• High Resolution Photo Available
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