New York, July 28. The speci:;l to the Tribune, Washington, 27 tli, síiys: " A reconnoitering forcé coiuinanded by General Gibbons, consisting of two regiments of hi. brigadoj ono of General Patiiek's, two batlulions of cavalry, oue from tlie llarris Liht Cavalry and o:ie from the Indiana cavalry, with a battery ot artilleiy, all bclonging to General King's división, puslied out from Fr'jilericksburii in tho direction of Gordonsville on Friday, and retuvned liist niglit. They advanced within nine or ten miles of Gordonsvilie, and uar]y to Orange Court House, whieh was oe cupied by a much superior force of the eiH'iny. "lluvinpc discovercd tliis fat-t, and hav ing securcd the object of the rccomioissauce, the expedition ruturned, hotly pursucd hv i Instile fofCO of cavalry wliich attaclcod tiia rcar gusrd sovcral tiiuea, biit. was repulsed ou each occasion with loss We hearof no loss on our sida. 'Gea. Popo takes tl.o fitild to-morrow. 'Tlio late order of Gen. Pope requirin; the residents within his linea wlio do not takts the oath of allegiance, to emigrate, is alrcady be;irinj; fruit in Friidt'i-icksburg Thirty of tlie kading rebels f tho town have gone to lliclimond with thoir familie, and othera are preparing to follow."