New York, Hept. 23. The World1 s special says Gen. Halleek has given an order for the Army of the Potomac to move forward. The situation on the Llupidan has undergone no material change on either side. The enemy is understood to be forlifying the approachee to Orange C. II., and Gordonsville. Lee's whole army it is estitnated is now composed of A. P. and D. H. Hill's corps, the latter evacualing Richmond lately to reinforce Lee, and Hood's división of Longatreet's corps, with Siuart's cavalry, making an ajgregate of 40,000 men. IS'ew Yoiik, Sept. 23. The Post't Washington letter of the 23d says: Gen. Meade's army is undoubtedly moving npon Gordonsville, and it wonla surprise no one hero that a battle was fought between him and Lee before Sunday. Lee stil! commandfl the army of Virginia, bnt his strength cannot be over 40.000. The etrength of Gen. Meade's army it would be imprudent to estimate, bnt, unless all reports which are sent up from the Rupidan are shainefully fulse, it is ready to offer battle to the enemy. Washington, Sept. 23 According to accounts from the Army of the Potomao received to night, a considerable portions oí onr troops have roached the northsidu oflhe Rapidan. A man carne into a printing office to beg a paper, "Becaiire," he faid, "we like to read newspapers very. much bnt our neighbors are too stinjjy to take one."