Pine’s Bridge over the Croton River, which is mentioned in the early history of the country, occupied a position which is now about the middle of this Reservoir, and there is at that place a bridge over the Reservoir resting upon piers and abutments. The hills which bound the Croton Valley where the Reservoir is formed are so bold as to confine it within narrow limits: for about two miles above the dam the average width is about one eighth of a mile; at this distance from the dam the valley opens so that for the length of two miles more the width is about a quarter of a mile; here the valley contracts again and diminishes the width until the flow line reaches the natural width of the River at the head of the lake. The country immediately contiguous to the shore has been cleared up, and all that would be liable to impart any impurity to the water has been removed. This gives a pleasing aspect to the lake, showing where the hand of art has swept along the shores leaving a clean margin. Retiring from the water are the richly cultivated slopes with the neat farm houses overlooking the lake, or the hills crowned with forest trees, while at intervals a valley or ravine opens and empties in its tributary stream. Plate IX. is a view taken above the dam showing the position of the entrance to the tunnel which leads from the Reservoir to the gate chamber at the head of the Aqueduct. The entablature which is seen on the left against the rock, is built directly over the mouth of the tunnel, and from this the tunnel extends through the rock to the gate house, which is seen on the right of the picture and some distance from the dam. The structure which is seen in the centre of the picture and on the ridge of the dam is a gate house over a culvert which extends through the body of the dam; this culvert is 30 feet below the surface of water when the Reservoir is full, and has gates which are operated by means of rods which rise to the interior of the house. During low stages of the River the water which is not drawn off by the Aqueduct may pass through this culvert and allow none to pass over the dam. The entrance to the tunnel is protected by a screen of timber work. Plate X. is a representation of the entablature over the mouth of the tunnel, showing the inscriptions upon it, relating to the date of the commencement of the dam and its completion, the persons who had contracts for building it, and those having charge of the work during the time. [Illustration: X ENTRANCE TO THE CROTON AQUEDUCT COMMENCED 1837 COMPLETED 1842 ] Plate XI. is a view taken from a point below the dam and shows the relative positions of the dam and the gate chamber at the head of the Aqueduct. The original channel of the River where the dam is built, was about 120 feet wide; the average depth of water at this place was about 4 feet; and the greatest depth 10 feet.