the temporary pipe at Harlem River, and is mainly to be attributed to the manner in which it was necessary to lay down this pipe, not allowing all the freedom of action that is necessary to provide for the expansion and contraction occurring in the different temperatures to which they are exposed. The aqueduct and its appurtenances have been subjected to the trial of near seven months, and I have endeavored to detail fully the effect the water has produced, and the prospect of its capacity to fulfil, with regularity and permanence, the object of its construction. It has been the subject of intense solicitude and care, and although there is

good ground to believe that in the main, the work will prove to have the stability and permanence that is necessary, it will still, for sometime to come, require a vigilant watchfulness. The deep interest I feel in the success of the work, as also its great importance to the city, inducesme to urge, that the persons to whose care it may be committed, be selected with reference to their acquaintance with the work, and their known ability and faithfulness, for the supervision required. After the work before mentioned shall have been completed, the ordinary work of supervision and repairs, if well directed, will probably be obtained at a moderate expense. At the same time it should be distinctly urged that economy or efficiency, can only be expected, from the supervision and care of men, who are intimately familiar with the method of construction and the character of the work, and who will deeply feel the high responsibility confided to their industry and fidelity. The main burden of this duty will consist, in an unwavering perseverance watching;