Mr, Henry L. Fitch, of San Francisco, has offered a prize of ten thousand dollars for the best treatise on the proposed Pacific and Atlantic Railway—the work to be written in simple and lucid style, and embrace the most thorough and exact treatment ot the subject in all its bearings. Mr. Fitch names a committee to met at Washington on the 15th day ot November next 5 and the manuscripts are to be sent to S. P. Andrews, New York City, before the 1S of November, 1853. Th above we take from an exchange.— We are not acquainted with any of the particulars, but at it h floated about considerably, we must say that we consider it a rare phenomenon. Who is this,benevolent gentle- man, Mr. Henry L. Fitch, of San Francisco who offers such a prize fora railroad treatise, and who is this S. P. Andrews?