The great railroad which was built by American engineers between Sk Petersburg and Moscow is 400 miles long, and has a double track the wllole length It is substantial ly built, and the trains run at the rate of 30 miles per hour For regularity and speed it perhaps has no equal in our country. As in all mora-cl ICPI court-ip ,*1 e-e a-eia-sof dif ferent grades for the people of different classes et for the 400 miles is fifteen dollars, for the secondcla s it is ten dollars,(urthe third six dollars. The grandees only ride in the nr t class ot cars the peasants in the third class, and the free merchants in the middle class JMessrs. irinans, of Baltimore, hae a contract for twelve years to keep all tli cars, engines, c, in good running order, nu to leave them all in good conditions at that time.