I would call the attention of the commanding general to the conduct of an association of engineers in the city of Saint Louis, who are interfering with men of their calling entering the service of the United States. Captain Porter, U. S. Navy, reports a case in point. He says that he sent to Saint Louis for an engineer for the tug Sampson. One was engaged, but, upon being informed by the association that they held a mortgage upon his property and would foreclose it if he accepted such service, was forced to decline.

U. S. GRANT,

Brigadier-General.

HEADQUARTERS DEPARTMENT OF THE OHIO,
Louisville, January 26, 1862.

Brigadier General S. P. CARTER,

Commanding Twelfth Brigade:

GENERAL: I have ordered your brigade to return to the Cumber land Gap route.

Take four of your best regiments, and perhaps four companies of your cavalry, if it should have come up, and by a prompt movement seize and hold Cumberland Gap, fortifying yourself strongly. Bring two sections of your artillery up to support you, leaving the other section, one company of cavalry, and one regiment of infantry at your depot of supplies, which, until you are surely established, had better remain at London, and afterwards move up perhaps to Barboursville.

I need not advise you how your advance upon the Gap should be conducted. Your baggage and a few days' provisions, protected by five or six companies of infantry, might move up to the fords, so as to be near at hand. From there your main column should move without baggage, except entrenching tools, and five days' rations in haversacks.

Your attack should be by skirmishers on the sides of the mountains, while a strong force in reserve holds and advances on the road. These details must be determined according to the circumstances as you find them.

The great difficulty which we have to contend with is that of supplying troops operating over so long a route, with the roads as bad as they are now at this season.

You must practice the most stringent economy in every article of supplies. Haul nothing that can be procured in the country or that can possibly be dispensed with. Detail a suitable number of trustworthy and efficient from your command to establish depots of forage along the route, say about three between Richmond and the Gap. It will be necessary to keep small guards at these depots.

It is difficult to lay down precise rules to govern you in the position which you are expected to take. With your force alone it is hardly to be expected, unless the enemy is weaker than is probable, that you should undertake any extensive operations.

The destruction of the railroad line through Tennessee is always important, but that, if you can attempt it at all, must be done by management or the rapid movement of a small force, rather than by any movement of your main force.

As a matter of policy, if for no other reason, and in order not to excite the rebel authorities to increased persecution of the loyal people