i Krom the Pliiladoljjhia l'n-.tKov. 21. As we udieatud yestu5"d:iy, the military iiuthoriiiegí a Washington huve detei'n.ioed to inake a (Jiversiofe in a different qunrter froto that now oocupied by lh,e aiiny of tho Potomac. - The vastness of tliis anny, vth its present oontraelod lim-s undatrong position, rendara it avalla ble of operalínn n various tü.ootions, aocording to the desjgnij of thy Commander-in-Chief Thy 1 lijnt ono of our rnost distingujah,ed generáis han exprossed thv [ipTóiun that to take Richmond now, we : must lemporaiily divert thc aoemy'e attention f'rom his present forti6e3 base of operatiocs, s, we tliink, enougli to wai runt us in tho beüef that no mme díate advanee upon Richmond will be made fren Predericksbilrg. The ap pidnciios by water to llie rebol cnta aro rnany, and so goad thíit we searcely know whiih fiijght prove the most advaiHageous n case ah espedítion je tiat vvhiuh failod on the Península should once more be sen t against Riohmond. Tho attraeíive baits to the rebel leaders, to be found at vari ons pointx along [he Southern eoaet, are not nlliiring enousfh an if coaxing will not bring the rebels qijt in their strengt h we must see what foi'C9 WU do. The question then opeurs fvnnfl what point should the íorcü bo applied, and who 8hiill niake the diversión ? Por suph a de[nonst-aioij ye have the efioiceol three points eiinontly eligiUlo 1, By tho way of York river, Idnding at West Point, twenty milos lielow Richmond. 2. I3y the way of Jame river, landing on the South bnnk at .the mouth of the Appomattox, about tv(uuy-fivo milos frorn Riuhmond, moving upon Port Walihall. and th reatening the rebel capital froni 'che rear, und cuiting it íf f'roin. raihvay oornmunipfltion v.ii'n the Southern Status. }. By way oí S'.ifínlk thrpugh Nanfemrid, Isle f Wigh:, Syu,thauipton, 31Ifisx, and Prinü' George countios, along ex cellont roads, throiigh a leve!, woll-watered plain, Beízing Bjanfprd Heights, ov.jrlookina; Peluisburgh. This is a march of fiñy-eight miles, In the lat ter movoment we wouid have the cover of gunboats in the Jarnes river, ii iioüdcd, and the privilege of landing reIntorcuments as high up as City Point, iwelve miles bolow Petersburg, and Cóggin's Point, iomteen miL-s below thatity. Suuli a course of procedure asihe latter was designed (qr Arniy oi the Potomuolast spring, b'Jt was chiimcd to be impracticable trom the fact that the Merrimsp was in existentie and tho Jan. es river not in our posession. A movement of this kind would now 1)089686 uil the grandeur ol that njqpped out for Gen. McClollan last ppnng, without the great difl};ulties whion inpeded our progress and flnally rendored our efiurts futile upon the Península. Uesides this, it would unshackle our weak columns upon the coast, now threatened with destruotion in detail, and render Washington entirely safe, as jt was so long as McClellan prosecute(J a flank tnoveinent toward ttie rebel capital. From Petersburg, a qavalry expedition would be neessary only to proceed west to the Burkesville Junctian of the Tennessee and Danville Bailroad?, and deatroy theni boh. It seems to us that if Potersburg were once in our hands, it would giva us virUially possosion of the entire South, and force Gen. Lee to tight his anny either to extorrninütion or submission, without any chance of retreat, or means of obtaining supplios or reinforcements frora the South and Southwest. Such a magnifleent diversion could now bo made without weakenjng the Army of the Potoinaü, the ex,pedtiun of General Banks or any other independent corps, except, perhaps, that of General Poster in North Carolina, and it would have the effect to give us a series. of dtcisive victories, whicb would putan end to the rebelljop before the enlistmeut of our '(mno months' volun'.tiors" is oqt, this, or some other similar diversión, should be made at once, to renner th,a capture of Richmond by Burnsido, certain.