LEAVENWORTH, KANS., August 16, 1861.

Major-General FREMONT,

Commanding Western Department:

SIR: Inclosed find the report showing our weakness. To-day I move upon Fort Scott, to stay the advance of the enemy into Kansas, and protect a large train turned back upon that point after the retreat of General Sigel. I hope to concentrate by Monday some 1,700 troops at that point, to fortify and to call on the people of that portion of Kansas to rally upon us. We should be re-enforced at the earliest possible moment with not less than three regiments. We should be supplied with artillery and small-arms, horse equipments, & c. Kansas is destitute. I have a thousand horses now arriving and eager men to mount them, but without arms or equipments.

Our men are without uniforms, blankets, or shoes. The Government promised to supply us, but as yet have failed. With supplies, when Sigel advances, i trust to operate upon the flank of the enemy to some purpose.

Let me hear from you at length. I send this by Honorable M. F. Conway and Mr. Coffin, superintendent of Indian affairs, who will more fully post you.

Yours, truly,

J. H. LANE.

[Inclosures.]

HEADQUARTERS KANSAS BRIGADE,
Fort Leavenworth, Kans., August 15, 1861.

General J. H. LANE, Leavenworth City:

GENERAL: Captain Blanton is getting his arms while I pen this. Colonel Leonard has called upon me, and states that he is just from Fort Scott, where the large Government train intended for Lyon's column has arrived and unloaded. The news of Lyon's battle had reached that place, and if, as admitted, Lyon's column has fallen back upon Rolla, it is of the utmost importance that the whole of Weer's regiment proceed by forced marches upon Fort Scott. If you concur with me in this measure, please inform me at the earliest possible moment. I propose to send the regiment, with sufficient rations to supply them en route, and follow up their movement with additional supplies.

Respectfully,

W. E. PRINCE,

Captain, U. S. Army, Commanding.

LEAVENWORTH, KANS., August 15, 1861.

Captain PRINCE:

I do fully concur that all the force we have should be concentrated at Fort Scott at the earliest possible moment and should fortify strongly, as also that Blanton should be removed to Humboldt, and fortify that point. I will direct an engineer to both points to mark out and superintend the fortification.

Yours, truly,

J. H. LANE.