In November 1913 the Paris Observatory, using the Eiffel Tower as an antenna, exchanged sustained wireless (radio) signals with the United States Naval Observatory, using an antenna in Arlington, Virginia to determine the exact difference of longitude between the two institutions.
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On September 28, 1850, the United States adopted two primary meridians of longitude for officially use: the Greenwich Meridian (through the old Royal Observatory at Greenwich, England) for all nautical and international use, and the Washington Meridian (through the old United States Naval Observatory in Washington, D.C.) for more accurate astronomical and domestic use.
At Georgetown Observatory, in 1850, Sestini made a series of sunspot drawings, which were engraved and published (44 plates) as "Appendix A" of the Naval Observatory volume for 1847, printed in 1853.
After returning from the expedition, Edwin Jesse De Haven served in the U.S. Coast Survey, before spending the rest of his career at the United States Naval Observatory under superintendent Matthew Fontaine Maury.