supporting columns, ready for the explosion on Sunday, September 24th. This being the greatest artificial explosion ever attempted, there was much trepidation shown in New York for fear of the shock, while everywhere the keenest interest was taken in the result. The blast was entirely successful, being discharged by General Newton's little child, who touched the electric key. The calculation had been so accurately made that the great reef was pulverized, and the fragments fell into the spaces excavated beneath without causing more than a slight tremor in the adjacent region. By a similar system and more extensive work, Flood Rock was afterwards removed from mid-channel, the second great blast reducing it to fragments, being discharged in October, 1885. The terrors of Hell Gate are gone, though the tide still flows swiftly through the strait. THE BROOKLYN BRIDGE. The growth of population on Long Island has caused various new bridges and tunnels to be projected for crossing East River. One new bridge is to cross at Blackwell's Island, with a pier on the island. Another now nearly completed, and estimated to cost $10,000,000, crosses from Grand Street to Broadway in Brooklyn. The Long Island Railroad is arranging to bore a tunnel under East River, to be operated by electricity, to bring its trains into New York. The East River being the locality for most of the foreign shipping, the bridges are at high elevations, the great Brooklyn Bridge, which crosses from City Hall Park, being one hundred and thirty-five feet above the water. Its massive piers are among the tallest structures about New York, rising two hundred and sixty-eight feet. This, the largest suspension bridge in the world, was begun in 1870 and opened for traffic in 1885. The piers stand upon caissons sunk into the rocky bed of the river, which is forty-five feet below the surface on the Brooklyn side and ninety feet below on the New York side. Their towers carry four sixteen-inch wire cables that sustain the bridge, which is built eighty-five feet wide, giving ample accommodation for two railways, two wagon roads also carrying electric cars, and a wide raised footway in the centre. The bridge cost nearly $15,000,000, the distance between the piers is about sixteen hundred feet, and its entire length between the anchorages of the cables is three thousand four hundred and seventy-five feet. The cable anchorages are enormous masses, each containing about thirty-five thousand cubic yards of solid masonry. The whole length of the bridge and its elaborate approaches is considerably over a mile. Its projector was John A. Roebling, who died during the early work, and its builder, his son Washington Roebling, who caught the dreaded "caisson disease" while superintending labor under water, and for years afterward an invalid, watched the progress of the later work from his chamber window on Brooklyn Heights nearby. The bridge has carried an enormous traffic, taxing its capacity to the