From Fredericksburg

The New York Time Falmouth special, States Unit t'o desertors .Trom the reliéis reporta Iheir forcé at 75 ta 160,000, curiuinly not exoeedirig the latter. Though suffer ing for want of clntliing and many kinds cf supplies, ttvey ure still appiirently hopefuloi finul sucoéfls. Leo and hw associates were. puzz'ed over thu roaveinents of our anny, whicli they do not neem to fully uöinpreheod, and hive finally concliided iho advanoe upon Frederioksburg ft feint, deigned to amue thein, while the muin attack npon Richiuond is tct oiiinu trom another quarter. Upon this theory they now heliova our foroè in front of Frederioksburg r reality to be pmall, and that i:nmenso host are being ernbarked at Bell Pliiins, and conveyed in transporta up Jame3 rlver. Acting upon this idea they have uommonced erecting earth-. v o; f ir the protectioo cf a garrison force, while tho main body of their orroy has níjain commnued moviog towaids Riohmondi