Just below the Custom House is the handsome marble building of Brown Brothers, bankers, one of the model houses of New York, as regards both the firm and the edifice. The Messrs. Brown are regarded as the most reliable and accomplished operators in the street. Across the way, in a dingy granite building, is the office of August Belmont & Co., the American agents of the Rothschilds, and bankers on their own account. Jay Cooke & Co. occupy the fine marble building at the corner of Wall and Nassau streets, opposite the Treasury, and there conduct the New York branch of their enormous business. Fisk & Hatch, the financial agents of the great Pacific Railway, are a few steps higher up Nassau street. Henry Clews & Co. are in the building occupied by the United States Assay Office. Other firms, of more or less eminence, fill the street. Some have fine, showy offices, others operate in dark, dingy holes. THE STOCK EXCHANGE. The Stock Exchange is located on Broad street, to the south of Wall street. It is a fine white marble edifice, extending back to New street, which is also taken up with brokers' offices. There is an entrance on Wall street, but the main building is on Broad street. It contains the "Long Room," the "The New York Stock Exchange," the "Mining Board," the now obsolete "Petroleum Board," and the "Government Board." All sorts of stocks are bought and sold in this building. "Erie" and "Pacific Mail" are the most attractive to the initiated, and the most disastrous as well. The Chamber of the Board of Stock Brokers is a large, handsomely furnished apartment, somewhat like a lecture room in appearance. Each broker has a seat assigned to him. Outsiders are not admitted to the sessions of the board, but any one may communicate with a member by handing his card to the doorkeeper, who will at once call out the gentleman. The sessions of the Board are presided over by a President, but the work is done by a Vice-President, who from ten o'clock until one, calls over the list of stocks, and declares the sales. Each day a list of stocks to be put in the market is made out, and no others can be sold during the sessions. The Board has the right to refuse to offer any stocks for sale, and a guarantee is required of the party making the sale. The members of the Board are men of character, and their transactions are fair and open. They are required to fulfil all contracts in good faith, however great the loss to themselves, on pain of expulsion from the Board, and an expelled member cannot be reinstated. The entrance fee is three thousand dollars. Persons wishing to become members are required to make their applications at certain times. This is publicly announced, and if any one can bring and sustain an accusation affecting the integrity of the applicant, he is not admitted.