| AT LAKE | AT CROTON | AT LAKE | AT CROTON | ||||
| COCHITUATE | BASIN | COCHITUATE | BASIN | ||||
| CU. FEET. | CU FEET. | CU. FEET. | CU FEET. | ||||
| January, | 99.17 | 92.48 | July, | 45.27 | 48.37 | ||
| February, | 150.42 | 147.69 | August, | 49.15 | 70.22 | ||
| March, | 174.76 | 177.02 | September, | 42.84 | 85.99 | ||
| April, | 169.80 | 132.63 | October, | 62.45 | 81.08 | ||
| May, | 131.80 | 164.49 | November, | 75.90 | 124.92 | ||
| June, | 44.27 | 115.12 | December, | 78.94 | 106.23 |
AQUEDUCTS.
The plan, as adopted by Mr. Hawskley at Liverpool, and Mr. Bateman at Glasgow, of subterranean pipes, is now universally followed by engineers. And there is no longer any excuse for incurring the outlay which must attend the erection of monumental structures, such as were necessary in the times of the ancient Romans.
The engineer of Marseilles Conduit adopted the “Pont du Gard” plan for conducting the waters of the Durance, in preference to iron pipes, and constructed the splendid folly, “as Humber terms it,” of the aqueduct “Roquefavour.” The dimensions are:
Length, 1,289 feet.
Height, 266 feet.
1st tier of 12 arches each 49½ feet span.
2d tier of 15 arches each 52½ feet span.
Upper tier of 54 arches each 16½ feet span.
The cost was $750,000, while inverted syphon pipes could have been laid for one-third of this sum.
The aqueduct for Glasgow is thirteen miles in tunnels, 3¾ miles of iron-piping across valleys, and nine miles of opening cutting and bridges. There are eighty distinct tunnels, and twenty-five important iron and masonry aqueducts. On the line is the Drymen bridge on masonry piers, eighteen feet apart, with two pipes surrounded by wood lagging, a forty-eight-inch syphon at Aberfoyle Road, and a lofty bridge at Ballewan, seventy feet in height.
The Aberdeen water-works has a thirty-six-inch syphon, 1,200 feet in length, across Cullen Burn, supported by granite piers.
The Croton aqueduct is a masonry channel lined with brick. The bottom is an inverted arch with cord 6.75 feet, and versed sine 0.75 feet; side walls are 4 feet high, and battered so that at the top they are 7′ 4″ apart, and surmounted with a semi-circular arch. The interior is 8.64 feet high, and area 53.34 square feet.