The other ten companies, under various names, I propose to unite into a battalion, and to muster them in as infantry on the same terms as Bissell's regiment; that is, to have the extra allowance when, acting as engineer troops. To effect this it will probably be necessary to break up the present organizations, so as to dispense in the new with the extra officers. The two companies of telegraph men and telegraph guards, 9 officers and 225 men, have already been mustered out, but many of them are ready to reorganize as infantry in the manner proposed.

The Engineer Corps proper, as it is called, has no troops, but probably about 50 officers. The names of 43 have already been ascertained, but some one turns up every few days holding a commission or appointment from General Fremont. Some of these are already discharged; but it is impossible to discharge them all at the present, their services being absolutely indispensable in the construction of the work which are now being built at Paducah, Cairo, Fort Holt, Rolla, Jefferson City, La Mine Cantonment near Sedalia, &c. The commanding officers at these places report that it is impossible to proceed with these defenses, now partially constructed, without the aid of one or more engineer officer at each place. I concide in their opinion, and shall be obliged to retain in service some 10 or 12 of the most competent of these officers, with the pay of captains and lieutenants of Engineers, until some arrangement can be made to replace them by regular officers.

I would remark that the pontier company has a large and costly bridge train nearly complete, and that the signal company has in its possession signal instruments, not perhaps, of much value for military operations, but which have cost a large sum of money.

The changes proposed will obviate the present irregularities and anomalies of organizatio; greatly reduce the expenses, and give efficiency to this branch of the service, which now seems to be without form and almost without use. I consider myself authorized by the instructions of the 2nd instant to make them, and shall do so as rapidly as possible, unless otherwise directed. The reorganization of the fragmentary bodies of artillery, cavalry, and infantry will be pushed forward with all possible dispatch.

I inclose herewith a communication of this date from General Cullum.* It is of vital importance that this request be granted. I have but one regular engineer and one topographical officer for duty in this department, and these have also to perform the duties of aides-de-camp. Important defenses are being contructed any competent person to direct them.

Very respectfully, your obedient servant,

H. W. HALLECK,

Major-General.

OTTERVILLE, December 14, 1861.

Major-General HALLECK, Saint Louis:

Reliable information just from Lexington. The rebels, 4,000 strong, left Lexington to-day to join Price, with large train. Prentiss, after firing several rounds into the town, fell back out of sight. I think there is no need to send to Lexington, but best to intercept rebels before they reach Warrensburg. Please reply, as force ready to move from Sedalia.

JNO. POPE,

Brigadier-General, Commanding.

---------------

* Not found.

---------------