One of the most valuable improvements of the last ten years, apparent to anybody who makes a trip out of the city over the Harlem road, is the depression of the tracks of that railway, so that from the Harlem River to above Bedford Park it nowhere crosses a public thoroughfare at grade. Magnificent avenues and parkways have been opened, and there is now in process of construction a grand concourse and boulevard which, when completed, will be the finest driveway in the world. The most conspicuous public improvement connected with the history of the North Side is the Harlem Ship Canal, opened to commerce on the 17th of June, 1895. After the tearing down of Macomb's Dam by Lewis G. Morris and his companions in 1838, there was no renewed attempt by private persons to obstruct the navigation of the Harlem River. Attention was given at various times to the question of dredging a navigable waterway through to the Hudson River, surveys were made, and two Harlem Ship Canal companies, organized by private capitalists, were incorporated. It was finally deemed expedient to undertake the work as a public enterprise, and the matter was brought to the attention of congress, which in 1874 ordered a government survey and in 1875 made the first appropriation. The work was planned by General John Newton, best remembered for his connection with the clearing of the Ilellgate channel. Tt was carried to completion under the direction of Lieutenant-Colonel George L. Gillespie, of the United States army. At the time of the opening of the canal, in 1895, 550.000 tons of rock had been removed, 102,000 cubic yards of earth excavated, 1,000,000 cubic yards of earth and mud dredged, 5,000 cubic yards of retaining walls built, and 2,000,000 tons of dynamite exploded. The canal follows the course of the Harlem River to near Kingsbridge, where it leaves the natural waterway and passes through an open cut in the " Dyckman Meadows" to its junction with Spuyten Duyvil ('reek.