Movement On Yorktown

New Yohk, April 8. The followiqg isa smnruary of ' ! gcnce reeeived by the War Departmeut up to toa o'clook Monday uight of the operations at Yorkfcown aid Fort Moaroe yesterday. Tac eneniy's workd wera earefully esamined by Gen. McClellap, and found to be very strong, ánd the approaclws difiieult. The enemy was ia and Uu; water batteries at York town and Grlóüflester -u-e s;iid to be increased. There was sharp Kring on the right lut no liüi-:.. fortes Wore rejsuppliös-frbm Sbip PoÍQt, . l up large traiua. - : tned plain that martars aud siega gans must be n.sod i'or aasauUing. Aii'. itoh reóeived at 10:50 atéá that Yorktown w i 11 I aot without a sieiro of two or three (.l.iyü. Some of' the outer worka wcre tiken. A dispatoh frona i-.;iWóol stal ■- thai Maruder bad 30,000 mun ;U VoL'kt.' On the aftéruoon of Sunday, Shift '■-A beca takeo ;uid our gunb heitcd thí batteries. delay causcd in erossing Deep Creek at Warwick. A inco was made by the rebels, during whicb time several casualties ujeurred oo pur s.th'. Al! the fortified places of importanoe ktown bad - Q at eveler accouut ia oontained in the foüowing di.sp;itcli : Vu::iiriv., Snturday, T.--i::;i_r. dwabI) M. Si'antox, Secretai'j' of A at : ' 'f his portiou ei' tho artriy of the Potoruao rcoeul)y eaüceutratjd at O!d terday rnorning iu tl. e directiön of Yorktown, fourteen inilea ut. ncd to G-a. Morcll's brigade of Ucn. P.prter's] división, twu couapanies of' tho 3d Pennsylvania cavalry and a portion of Berdan's Sharpnuisliors. " Notiiin of interest took place unül their arrival at IJig Bethel, twelve miles , where thej mt the outer picketa of the rebels. T!ie troops wcro delayed herc t.-.ü honrs, cónstructiDg a brid3 d ucstroycd. Tí: irc;ited before the advance cf our skirniishcrs to Howard Creek, where they had some abandoned earth works Shots were fired bere by Hila t'v m tv; field pici's, wbich wcre a ; the -íth líhodo Is.. , when tho robels beat a hasty retreat, takuig their pieees t'aem. ' The m:in body of the anny rested r the night, whüe Moreli's brigade advaneed t lire e miles to Cookleville, six miles frota Yorktown. 13y sevcn o'elock this (Saturday) morning the column was nguju in ïnotion, aud by ten o'elock was in front of the enem'a works at Yorktown. ''The fiistsbot was fired by the rebels, the shell passing over the heads of General Porter and staiF without explodjog. - Tho batteriea of (iriffin's tbird, the 4th 15hode Island acd 5th Ma.-sachusetts wera placed in positron; replyiog at every shot sent by the n k Xhv c d inuöd with lut intermissiou until dark. ibout four J:undred shots werc fircd by both partiés fiuriüg the day. " " The ioss on our sido was some threo kiilo-1 and five woanied. '■ The positioa oí the reuels ia a strong one. Frora present indicatiöns their forüfioatiooa extend some two miles in a i mount heavy guns. " Tho ground iu front of their guus ia low and Bwampy."