This estimate proved approximately correct, the total cost being $19,255.49 per mile, a trifle over one-half of the cost per mile of the Chesapeake and Ohio Canal. The success of the Erie Canal, shown by the tolls received from 1825 to 1834 ($8,539,377.70), was more than its promoters had expected; indeed it was so great that the enlargement of the canal was rendered imperative within a decade. This was first urged by the citizens of one of the jewel-cities made by the great waterway--Utica. The memorial now reported to the legislature by E. F. Johnson called for a steamboat canal from Utica to Oswego (Lake Ontario) which was to be extended to Albany; the proposed depth was eight feet, width fifty-eight feet on the bottom and ninety feet on the surface, the locks one hundred and thirty feet long by thirty feet wide. "On the Erie Canal," the memorial urged, "the cost of animal power is 12 per cent greater than steam power on the Hudson for flour, and 42 per cent greater for merchandize; agricultural products, including ashes, 21 per cent greater on the canal than on the Hudson river. The Erie canal is small, and the traction of boats that navigate it is from 30 to 45, and most usually 40 per cent greater than would occur on a canal of the most favorable size for the boat used.... That a canal boat, 104 feet long, 16 feet wide, drawing 7 feet water, would carry 200 tons, and require a lock 115 feet long by 17 feet wide; the sectional area of boat below load water line 108 feet. The gross load of a schooner, with its own weight, would be 350 tons. Canal boats, constructed with reference to freight merely, will generally weigh in the ratio of their cargo as 4 to 9."[57] Engineer N. S. Roberts in a report dated January 17, 1835, said: "The present canal admits boats 13-1/2 feet wide, 3 feet draught, 80 feet long, displaces 80 tons water, weight of boat 30 to 35 tons, cargo 45 tons. Size of canal, 28 [26?] feet bottom, 40 feet surface, 4 feet depth cross sec[tion] = 136 [132?] sq. feet. Enlarged canal to reduce cost of transportation, 43-3/4 per cent must be 33 feet bottom, 48 feet top, and 5 feet deep, cross sec[tion]: 202.5; width and size of locks: 15×110 between gates, admitting a boat 102 feet long, 13-1/2 feet wide, and 4 feet draught."[58] After examination, the canal board determined to make the canal seventy feet wide on the surface, seven feet deep; the locks were to measure 110 feet between quoins and be eighteen feet deep. It was estimated that a canal of these proportions would save fifty per cent of transportation charges exclusive of tolls.[59] The enlargement construction law was passed May 11, 1835; the act called for the construction of "double locks thereon as soon as they should deem it for the public interest; the dimensions of the canals and locks to be fixed by the Canal Board."[60]