Gap, under Major Gilmor. No reliable rumor about number. Major Thompson has had out all my available horses since Friday night. They return this p. m. Unless you wish the reconnaissance to Leesburg made immediately, I shall delay twenty-four hours that the horses may rest.

Very respectfully,

C. R. LOWELL, Jr.,

Colonel, Commanding Cavalry.

YORKTOWN, August 30, 1863.

General NAGLEE,

Norfolk:

Rebels had several squadrons of cavalry at Urbanna withdrawn to Richmond in great hurry Friday night in consequence of our demonstration above. They have got at Urbanna Creek the captured gunboats and schooners and some of our wounded from that affair. Onderdonk's horses cannot move before Tuesday. I will before then submit to you my plans. Rebels are trying to move gunboat machinery to Richmond overland.

I. J. WISTAR,

Brigadier-General.

HEADQUARTERS,
Near Suffolk, August 30, 1863.

General GETTY:

I received your dispatch of last evening at 9 p. m. I send my wagons for five days' forage and rations. Also send for proper papers, data, &c., for completing muster-rolls. I returned at 3. 30 this morning. Nothing new. Cannot coax Griffin or Baker to cross the Blackwater. Same force as last reported.

I send a deserter named John H. Crawford, Eleventh North Carolina Battalion, and a captive, Richard Rhoades, Company L, Sixty-second Regiment Georgia Cavalry (Colonel Griffin's). I have examined both and obtained nothing definite.

I think the order for remaining here a good one, and should have recommended it this morning had it not been received; as I believe the moment I left the crossing would commence, at least it appears so from the present force now there "for some purpose. "

Animals improving. Men in good health and spirits. I start again to-night in direction of B. W. [the Blackwater]. Will keep you well informed of anything new.

I am, general, with high respect, your obedient servant,

S. P. SPEAR,

Colonel, Commanding Expedition.

SPECIAL ORDERS,
HDQRS. U. S. TROOPS IN CITY AND HARBOR, Numbers 41. New York, August 30, 1863.

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III. Brigadier General Thomas H. Ruger, commanding Second Brigade, will order the Third and Fifth Regiments Michigan Volunteers (the former now at Numbers 41 Chambers street, the latter on Governor's