A large portion of them are intended as ventilators to discharge the superabundant air collected in the aqueduct, and a few of them are fitted for waste weirs, for discharging the water from the aqueduct, if at any time repairs should be required, or any other cause make it necessary. There were six complete on the first of July last, making an increase of eighteen in this description of the work. Besides the foregoing, there has been a great deal of work performed, which cannot be described with the necessary degree of accuracy and plainness to make it understood, such as earth and rock excavation, which has been performed before the grade of the aqueduct could be reached ;

embankment and backfilling, performed after the aqueduct is in form, &c. There is still about six and a half miles of aqueduct to complete, in the county of Westchester, and about seven and a half miles of aqueduct and pipe work, on the island of New York, making the length of the unfinished work, about fourteen miles.

This was a very trying year for financial arrangements ; nevertheless, the city continued to face all its engagements with punctuality, and to meet the great expenditure on account of the aqueduct ; and the Commissioners, although not charged with any agency in raising the money needed for the work, nevertheless express their clear conviction that it

would be better to pay higher interest, if necessary, for the amount required for the next year, than to incur the loss of interest, the claims of damages from contractors, and the unavoidable injury to the unfinished works, that would result from a suspension.