a rule to consideratcause to be tested any which seem to be of value.

There have been thus examined signal rockets, composition fires, telescopes, and binocular glasses signal pistols modes of discharging lights, instruments for electric telegraphing, insulated wires for field use, and plans for using field the telegraphs.

From these experiments have been gained experience and results of some value.

I recommend that for the ensuing year the sum of $3,000 be estimated for such trials of this character as may be necessary.

COUNTERSIGN SIGNALS.

At the date of my last report a plan of countersign signals by which to avoid the collision of friendly regiments, had just been adopted.

These signals, with instructions as to use, were issued to more than 200 regiments. It is certain, so far as I can judge, that accidental collisions can be made almost impossible, and friendly regiments can be distinguished either in battle or on the march. But in an army of new troops, to properly discharge this duty, it needs that there be attached at least one signal officer to a brigade, to supervise this, with other signal service. This proportion was estimated and provided for inan act last year submitted to Congress. No matter what the danger, other officers cannot, in such armies as ours in the field, properly attend to this duty. The failure of Congress to pass at its last session the act organizing the corps rendered a detail of this kind impossible. It can still less be given with the Army increased as now.

In view of these facts, and the difficulties attending the immediate furnishing of supplies, I have recently recommended the suspension of the use of countersign signals in the Army of the Potomac. If the management of countersign signals is not properly superintended they become a source of danger. If it is not the will of Congress to appoint suitable officers for this duty, and in numbers sufficient, I recommend that it be not extended. The loss of life from accidental firing will, it is probable, not be greater than it might be made if signals werhands of regiments and not rightly used. The sum placed in my estimate to enable their use to be continued in some armies, and increased, should it be desirable to do so, is $20,892. It is advisable that this office should not be without the means for this purpose.

FIELD TELEGRAPHS.

In my report of November 30, 1861, submitted through the then General-in-Chief, I related the efforts made from the beginning of this war to bring into the use of our armies movable electric trains. Estimates were at the same time submitted.

It was then, and for some time after, difficult to induce a wise or even careful consideration of the subject. One train was, however, partially completed.

With the first movements of the Army of the Potomac the want of such trains was felt. On March 30, 1862, I again submitted estimates approved by the general commanding the Army of the Potomac, for funds to be placed in the hands of the signal officer for the construction of such apparatus. No information has been received in regard to these estimates.