HEADQUARTERS FIFTH ARMY CORPS,

October 1, 1864--evening.

Major-General MEADE:

GENERAL: From what I know of our and General Lee's relative strength I do not think we can extend our lines further around Petersburg without great risk. If we design, by such continued extensions, ultimately to make him abandon Petersburg, and if the complete envelopment of it from riverbank to river-bank is practicable, I think it altogether to be expected that when we reach our fullest development he will, by a concentrated effort, break our lines and compel us to fall back to the James with much loss of material. If Petersburg is worth the efforts we are making, it is worth that effort from General Lee, and he will make it before evacuation of the place. Now, I would propose the establishment of a very strong position on the Weldon railroad, with a supply of stores and competent garrison, and then, assembling all our force, place ourselves on the South Side Railroad and destroy it. This would undoubtedly bring on a general battle, which would decide whether General Lee could keep the field against us or not. If he could not, we should thus compel him to retire within his defenses, and a siege proper could begin. If he beats us, we can retire upon the position on the Weldon railroad or upon the James. This last is a supposition which our calculations do not admit of. If it be said General Lee might refuse us battle and come out between us and our base and fortify, we could prepare several roads to the James on winch to retire for supplies if necessary; or we could attack him or Petersburg: one of which would be held by half or less of his force. If we go on as we are going, with our ultimate point of occupation so distant, we shall finally become powerless for offensive operations, perhaps before it is reached, all our forces being required to hold our lines against attacks from the front or cavalry raids in our rear. We need time to get our new levies in order, and no matter how great the pressure, we cannot succeed with them till they have at least acquired the knowledge of the rudiments of their drill and discipline. Another effect of our operating at the same time on two such distant flanks is to make the commander at each point apprehensive of being greatly outnumbered by the enemy, which is always practicable for him to do at one or the other, and thus inevitably produce want of boldness and vigor on our part, unless we neglect more than any of us are willing to do. Then, I would again urge, let us give up all our investing line, except one point at most, and again take the field with our whole army. I do not wish to urge my views for any personal object, nor wish them to be considered as finding fault with other plans, but I am so convinced of the justness of what I advance and of its importance to our corps that I present them to you at all hazards, and you are at liberty to make use of this communication in any way you please to.

Respectfully submitted.

G. K. WARREN,

Major-General of Volunteers.