Since early this morning the weather has been too squally to admit of ascending with the balloon. Every opportunity, however, shall be improved and reports made.

Very respectfully, your most obedient servant,

T. S. C. LOWE,

Chief of Aeronautic.

HEADQUARTERS ARMY OF THE POTOMAC,
March 17, 1863.

Professor LOWE,

Balloon Department:

PROFESSOR: The major-general commanding directs that you make an ascension, if your balloon is in readiness, immediately after dusk, or as soon as rockets with their colors and fires are visible; that you report the color, &c., of rocket-if any can be seen-in a north northwesterly or westerly direction. The colors expected are to represent signals as follows:

One signal green; one signal, green and red; one signal, red and white; one signal, red and green; one signal, white and red. Answering signal from intermediate stations, green. Knowing what signals are expected, you can, perhaps, more readily and surely discern them. Report with care.

Very respectfully, your obedient servant,

PAUL A. OLIVER,

Lieutenant and Aide-de-Camp.

HEADQUARTERS CAVALRY CORPS, ARMY OF THE POTOMAC,
March 19, 1863.

General S. WILLIAMS,

Assistant Adjutant-General:

Professor Lowe has an arrangement for transmitting information from distant points by signal balloons, which I think might be made available and valuable with cavalry operating in the field. I have though the subject over a good deal, and if the professor can get authority to procure the necessary apparatus I will take measures to test and, if possible, put his plan in practice.

Very respectfully, &c.,

GEORGE STONEMAN,

Brigadier-General, Commanding Corps.

[Indorsement.]

HEADQUARTERS ARMY OF THE POTOMAC,
March 19, 1863.

Respectfully referred to Professor Lowe, with the request that he will please state in substance the preparations the proposed plan will require and the probable expense of the same.

By command of Major-General Hooker:

S. WILLIAMS,

Assistant Adjutant-General.

HEADQUARTERS AERONAUTIC CORPS,
Camp near Falmouth, Va., March 20, 1863.

Brigadier General S. WILLIAMS,

Assistant Adjutant-General, Army of the Potomac:

GENERAL: In answer to your inquiry concerning the preparation and probable expense of testing my plan for signals by balloons, I would respectfully state that the preparation will consist in getting the balloons made of the proper material and sizes with proper attachments; constructing a variety of characters to be attached to the balloons for day signals; arranging a variety of different colored lights of great power and brilliancy in order that they may be seen a great distance. The time required to get everything ready, I think, would be about one week. The arrangement once completed, any person of ordinary intelligence can use the signals. The cost of thoroughly testing will not exceed $300, after which, if brought into use, the cost of each balloon for conveying signals will not exceed $6, where a quantity is ordered at one time.

I remain, general, very respectfully, your most obedient servant,

T. S. C. LOWE,

Chief of Aeronautics, Army of the Potomac.