Échange de cartes pour observer les Pléiades

[To] Prof. Quetelet, Director of Observatory Brussels
Coast Survey Office, Washington City, Nov. 1857
Dear Sir,
I have the honor to send herewith a chart of the Pleiades occultation of December 27th, as visible at your observatory, designed to facilitate their observation.
Arrangements have been made for observing the same at many places on this continent, and it is hoped that you will find it convenient and practicable to make corresponding observations, which you will confer a favor by communicating to me.
You would also oblige me by stating whether you would like to receive similar prediction charts for futur Pleiades occultations, visible both in Europe and in this country.
Yours very respectfully
[signé] A.D. Bache
Supt. U.S. Coast Survey

Sunday, 1 November, 1857 - 00:00
Written by: 
Alexander Dallas Bache, superintendent U.S. Coast Survey
Addressed to: 
A. Quetelet