This was done for the purpose of ascertaining by experiment, what form and size will be best suited for fountains, which may be erected in the public squares or other parts of the city, for convenience or ornament. The jet is generally allowed to play a few hours in the afternoon of every day, and the large volume which it throws to the height of 110 feet, is an object of much interest to those who visit this, at present, most interesting spot. HARLEM RIVER BRIDGE. The progress of this work, since our last report, has, owing to several causes, been slower than we expected. In that report it was mentioned that after carrying the excavation for pier No. 10, thirty-four feet below the surface of the water, without finding rock, it was determined to place it upon piles. In carrying out this determination, 240 bearing piles have been driven, varying in length from 30 to 36 feet. Cross timbers were laid upon the heads of these, and the spaces between these timbers filled with concrete. Upon the timbers, the cut stone masonry was commenced, and several courses of this are now laid. All the difficulty and danger inseparably connected with the use of coffer dams, of the great size and depth required for this pier, have been successfully overcome, and the masonry will, in a few weeks, be raised above the high water of the river. The coffer dams for piers Nos. 11, 12, and 13, are in their places, and embanked, but none of them have yet been cleared of water, or the character of the foundations ascertained. It is expected, however, that 11 and 12, and perhaps