Id Bivouac at Kelly's Ford on the . í Rappahannock, Tuesday - 10 P. M $ The Rappahannock is again crossed by the Army of the Potoinac, and this tima without the shedding of a drop of blood, or the firing of a single gun. The great movenient which we have been so long auticipating begun iu earnest at daylight on Monday morning, by the movpmeut of a heavy force up the Rappahanuoek. Tho Eleventh Army Corps, Gen. Howard, bad the advance oo the march, and stül has ifc. At this hour it is hardly prudent to enter into the minute details of the foroo and the march, as they have undoubted'y a great deal of work yet before them. The weather on Mouday was reraaikab!y fine - even sultry, and the men fouud marching in overcoats toofatiguing. They threw them away in largo numbers, and the track of tbe column can ba traccd by the abandonetl clotiii;:g Tuesday mornïug we had u cloudy sky, and before 0 o'ulock a drizzling rain bogan falling. But our column kopt Bteailily moving, and by 1 o'clock Gen. Huward's advanee arrived at Mount llo!l)r Church, one mile from Kelly's Ford, having marched tsixteen miles since dsylight. The rain coutinued until the muidle of the afternoon, when itceased, it havi'ig at no timo been very severo, but just cnough to m;iko uaarohmg heavy, and to stall ono or two ol our very s:nall number of wagons in soine of the chroaio mud holes. Otherwise, tho move prospered. The arrival of the troops in vicinüy of tho Ford was well maskcd by Col. Bushbeck's brigade, of the Eleventh Corps, who had beeu gunrding the post for two weeks. The troops marched rapidly and in fino spirits. Slooum caniped last night ne;ir Hrrtroad Church, and Meade just east of it - all wcre well up by 4 P. M. to-d:iy. At 8 this morning Gen. Hooker left his headjquarters, and accompauied by his personal stafF, rode straight to Morrivilh', 20 miles distance, and but six milus to the Ford. His passage through various columns of troops was marked for miles by a tumultuous cheer, enthusiastically genuino. At Morrisvilla ho makes his headquarters for the d.iy and night. A consultation of corps commanders, inoluding Gen. Stoucman, who had come from Warrenton Junction, was at once held, and thcu and there Gen, Ilooker first revealed to these, hü principal subordiuates, a portion of the plan and nature of the present movoment. Beyond what li'ts been already devel&ped, none but these officers know anything. Yet there is ronain to believo that it is startling in the magnitudo of what it contetnplates, and general officers remar kad this afteruoou that if officers and men did onehalf tbeir duty, it oould not fail of suocess. Howard rested his men four hours. and they wcre then got uuder arms ready to support tho operations at the ford. The poutoon train for the bridges arrived with great proinptnesa, having ooino from Boaltcn Station, boiug trans ported thither by a railroad from Alexandria. They are tho usual wooden boac, save being suialler in eize than those formerly ustd. The pontoons and timbar were all unloaded on the bank of Marsh Creek ; near its mouth, and the boats launched beforo dark. Tbeso operations, be it known, were oonduoted in plain sighfc of the encmy, ' who sppeared only in sinall force - a few ' straggliDg pickets, who seemed to be ' there as lookouU only. They kept a fharp watch, but not a shot was firod - f Tbe vutk we-t rapidly on. Th ' toons were at onoc shoveri from the moutli of Marsh Croek intn the Rnppahaunogk. Seveuteen boat luads oí' moa from (Jol Bushbtok's brigade were thrown over at once, followed by a l'cínforceinent of as iiianv more. The bndgclayii'g began it 8 o'elock, and proceeded vigorously, under tlio di rection of Capt. ('omstock, Engineer Officier on Gen. Hooker's Staff. ]}y 9.J P. M., ono bridge was coiripleted and another undcr way. Howard's corps was put uiuler mQtion for orossi-ng, L'ushbeek's brigade leadiog, followed by Sehurz' división, thon by Diven's, the balance oí' Vou Steinwehr bl'iuging up tbs rear. This foicc was disposed on the south bank for the night, doing pieket j duty on the different roads. Just before our forcea landud, a small body of oavalry, numbering twenty, perhaps, daahed down uearly to the rivor, and fora short time, loisurelj' survejed our operatious and then retired. That thero was no resistanee at the Ford caused much surprise. Not a shigle shot was fired. Thfi eneniy had rifle pits, but di J not use tbeui. We took no prisoners. Tbei'8 is the best reason for believing that up to noon to day the eneniy had not discovered this inoveinent. Every citizen on tlie line of march was put and will be kept onder close, guard uatil tliey ean do no damage Wo spceulato freelv on the cvents of the inorrow ere we reacïi our destination, which is Gul pepper on the one band, and Ely's Furd, on tho Sftapidan, on the other. We shall undoubtedly meet the cnciuy before we reach either place, though each are less i than a day'n march distant. Síuart's i cavalry have Dot shown themselves to : auy txtent, and Fitz Hugh Lee is reported absent, sick. We are certain of one or more ! T here are no heavy fortilications in front of us, there aro no very strong pcsn:o:s ' whieü can ba defended. The euemy must have as strong a forcé as oura to j beat us back. Bridges will undoubteilly be laid at I other fords further down the river, for the benefit of our transportaron, which is iq a safo place. Once well acrosa here, we ean protect tho bridges at anv of the fords below. The sun set clear and red to night. nd gave proraiso of a fair day to morrow. But the night is thick vvith mist, and the moon is "eating fog," which sailora say is a sure sigu of a coming storm.