Pearson, Esq., an architectural draftsman, now in the employ of the Commissioners, which are herewith submitted for the inspection of your honorable body. The chief engineer expresses a decided opinion in favor of the plan by inverted syphons or pipes ; and the Board of Commissioners, after due deliberation, have adopted said plan, as, in their opinion, far preferable to that for crossing by a high bridge and inclined plane. The reasons which have governed the Commissioners in this decision, are as follows :

1st. The difference in the cost of carrying an aqueduct over the river, on a bridge of 163 feet in height, on seven immense stone piers, sunk in the water and mud, on an average of 25 feet below tide, with 80 feet span of arches, and that of conducting the water over a low bridge, requiring only one pier in the river, with an abutment, is sufficlient of itself, in the opinion of the Commissioners, to decide the question.

152 MEMOIROFTHE 2d. All the purposes and objects to be obtained by the project, will as well be attained by the plan of a low bridge as by that of the high bridge, and at an expense of more than half a million of dollars less. 3d. The experience in sinking piers in so great a depth of water and mud, in order to reach the rock bottom, being very limited, and their great number and immense height from the rock to the spring of the arches, although their construction is practicable, it must be attended with many unforeseen difficulties and casualties and should the least ;