National Academy of Sciences.

The annual *stated session* of the NATIONAL ACADEMY OF SCIENCES will be held in Washington, D. C., beginning Tuesday, April 21, 1891, at 11 A. M.

The place of meeting will be at the National Museum.

The Council is requested to meet at half-past ten A. M.

An election for Vice-President of the Academy will be held at this meeting.

A list of candidates nominated for membership is enclosed here with; also an envelope, in which the ballot for preference may be sealed, and enclosed in another envelope addressed to the Home Secretary. On the latter the name of the sender should be endorsed. The former envelope will be opened only by the tellers.

Members who intend to present communications are requested to send the titles to the Home Secretary before April 20, so that a programme may be printed.

The time required for the reading of a paper should be stated.

A. HALL,

Home Secretary.

NAVAL OBSERVATORY, WASHINGTON, D. C.,

March 17, 1891.