The flow of water through the pipes across Manhattan valley, and also the temporary pipe across Harlem river, being attended with circumstances somewhat different, has led some very intelligent persons to predict, that our expectations would not be realised in these cases it therefore maybe proper to observe that trial has ;

proved such predictions to have been not well founded, as the flow through the pipes has in a very exact manner corroborated the anticipated capacity, as compared with that in the aqueduct. -

The Croton reservoir, (which has received the name of Croton lake,) covers about 400 acres of land, find is available as a reservoir for 500,000,000 imperial gallons of water, above the level that would allow the aqueduct to discharge 35.000,000 gallons per day. The flow of the Croton is about 27,000,000 gallons in twenty -four hours at the lowest stages, which continues, with moderate rises by occasional rains, from two to three mouths in the year. This may be considered the minimum capacity of the river. When the wants of the city shall require a daily supply of 35,000,000 gallons, it will be necessary, during the season of lowest water, to draw daily from this reservoir 8,000,000 gallons, to make up the deficiency in the natural flow of the river. This amount the reservoir would supply for 62 days, without any aid from occasional rains which may safely ;

be relied upon, to keep up the required supply from the reservoir, beyond any drought we have ground to apprehend. The supply of the Croton, from its daily flow, aided by this reservoir, may therefore be taken witfrgreat confidence at 35,000,000 gallons, which will be very ample for the wants of the city for a long time to come and when the day ;