On the ground floor, we find, in the first place, the rooms that the contractor is to furnish gratuitously for post office, telegraph, and telephones, and to licensed brokers, and especially a hall of superb dimensions designed for the public sale of raw materials by the brokers. What remains of the ground floor will be devoted to offices looking at once upon the hall and Viarones Street. The entresol and the two stories will be connected by several staircases. The various stories will also be reached through elevators. A circular balcony will extend around the hall at the level of each of the two upper stories. These will be occupied by offices smaller than those on the ground floor, which will, some of them, get their light from the hall, and others from the street. A part of the second story will be reserved for the service of the committees on grain and flour, who, as experts, are called upon to determine to what type each specimen is to be referred. From the exchange, let us pass to the annexes. The one on the right is destined to become a large hotel for the accommodation of provincial and foreign merchants. The one to the left will be a tenement house, with shops and apartments. Along each of these annexes, on Viarones Street, will extend a covered colonnade.--_Abstract from Le Genie Civil._ * * * * * A BASIS FROM WHICH TO CALCULATE CHARGES FOR ELECTRIC MOTOR SERVICE.[1] [Footnote 1: Read before the electric light convention, New York, August, 1888.] The theoretical side of the electric motor question has been very ably presented to and discussed by this association, but thus far the practical side has been somewhat neglected. It will be my purpose in this paper, if possible, to show that there is a general average controlling the use of machinery which it will be safe for electric light and power companies to follow in making their charges for motor service, rather than adopt an arbitrary price per horse power regardless of the character of service required of the motor. I have arranged what might be called a power curve, representing the approximate average actual service in electric motors in connection with the several classes of work represented in the list accompanying the diagram. This curve is calculated on motors which are only of sufficient capacity in each case to carry the full load. If the motor should be larger than is necessary to drive the machinery, the percentage of actual service will, of course, drop below that shown in the diagram.