In ordering this boat the French government stipulated a speed of 6 knots to be maintained during three hours with an expenditure of 10 horse power. The result of the trials gave a speed of 61/2 knots during five hours with 12 horse power, and sufficient charge was left in the accumulators to allow the boat to travel on the following day for four hours. This performance is exceedingly good, since it shows that one horse power hour has been obtained with less than 60 lb. of total weight of battery. * * * * * THE COMMERCIAL EXCHANGE, PARIS. Leveling the ground, pulling down old buildings, and distributing light and air through her wide streets, Paris is slowly and continuously pursuing her transformation. At this moment it is an entire district, and not one of the least curious ones, that is disappearing, leaving no other trace of its existence than the circular walls that once inclosed the wheat market. It is this building that, metamorphosed, is to become the Commercial Exchange that has been so earnestly demanded since 1880 by the commerce of Paris. The question, which was simple in the first place, and consisted in the conversion of the wheat market into a commercial exchange, became complicated by a project of enlarging the markets. It therefore became necessary to take possession, on the one hand, of sixty seven estates, of a total area of 116,715 square feet, to clear the exchange, and, on the other, of 49,965 square feet to clear the central markets. In other words, out of $5,000,000 voted by the common council for this work, $2,800,000 are devoted to the dispossessions necessitated by the new exchange, $1,800,000 to those necessitated by the markets, and $400,000 are appropriated to the wheat market. The work of demolition began last spring, and the odd number side of Orleans street, Deux-Ecus street, from this latter to J.J. Rousseau street, Babille street, Mercier street, and Sortine street, now no longer exist. All this part is to-day but a desert, in whose center stands the iron trussing of the wheat market cupola. It is on these grounds that will be laid out the prolongation of Louvre street in a straight line to Coquilliere street. Our engraving shows the present state of the work. What is seen of the wheat market will be preserved and utilized by Mr. Blondeau, the architect, who has obtained a grant from the commercial exchange to construct two edifices on two plots of an area of 32,220 square feet, fronting on Louvre street, and which will bring the city an annual rent of $60,000. [Illustration: THE NEW COMMERCIAL EXCHANGE, PARIS.]