The whole line having been found in good condition, orders were given to close the openings which had been left in the bottom, for the escape of water which flowed into the work in tunnels and deep cuttings. This having been done, and the dam raised sufficiently to cause the water to flow into the aqueduct, it was admitted to the depth of 18 inches, at 5 o'clock in the morning of the 22d June. A boat capable of carrying four persons, which had been prepared for the purpose, called the " Croton Maid," was then placed in the aqueduct to be carried down by the current. She was navigated sometimes by one portion of the party, sometimes by another, during her singular voyage, and arrived at Harlem river almost simultaneously with the first arrival of the water. The velocity with which the current flowed in the aqueduct was a matter of great interest, and therefore carefully observed ; and we were much pleased to find that it was at a quicker rate than the calculations of the engineers had led us to expect. The velocity observed at that time was a mile in 40 minutes but subsequent observations, with the ;

depth of water increased to 2 feet, have shown that it flows a mile in 36 minutes, and with a depth of 4 feet, the velocity will probably not fall far short of 2 miles per hour. On the arrival of the water at Harlem river on Thursday, the 23d June, formal notice of the event was given by the Commissioners to the Mayor and Common Council, who were also informed, at the same time, that it was our intention to admit it into the receiving reservoir at Yorkville on the succeeding Monday.