| NAME OF WORKS. | NAME OF | MAXIMUM DEPTH | RATIO OF | |
| RESERVOIR. | OF RESERVOIR. | SLOPES. | ||
| INNER. | OUTER. | |||
| Bolton Water-Works | Heaton. | 35 | 3 to 1 | 2 to 1 |
| “ “ “ | Wayoh. | 76 | “ | 2½ to 1 |
| Liverpool | Roddlesworth. | 64 | “ | 2 to 1 |
| “ | “ | 78 | “ | “ |
| “ | Anglezark. | 35 | “ | “ |
| Bradford | Stuben. | 55 | “ | “ |
| “ | Chelker. | 36 | “ | “ |
| “ | Barden. | 68 | “ | “ |
| “ | Doe Park. | 52 | “ | “ |
| “ | Silsden. | 78 | “ | “ |
| “ | Gwmwith. | 66 | “ | “ |
| Rhyl District | Llanefwydd. | 52 | “ | “ |
| Warrington W. W. | — | 13 | 1½ to 1 | “ |
| NAME OF WORKS. | PUDDLE WALLS. | WIDTH | WIDTH | |||
| MAX. | THICK- | THICK- | OF TOP | OF DYE | ||
| DEPTH. | NESS AT | NESS AT | BATTER. | BANK. | WASH. | |
| SURFACE. | TOP. | |||||
| ′ | ′ ″ | ′ | ′ ″ | ′ | ||
| Bolton Water-Works | 6 | 8 3 | 4 | 1 in 15 | 13 6 | 12 |
| “ “ “ | 70 | 20 6 | 8 | 1 in 12 | 22 | 105 |
| Liverpool | 120 | — | 6 | 1 in 12 | 16 | 60 |
| “ | — | — | 6 | 1 in 12 | 18 | — |
| “ | 50 | — | — | — | 30 | — |
| Bradford | 40 | 12 | 6 | 1 in 18 | 12 | 15 |
| “ | 30 | 12 | 6 | 1 in 12 | 12 | — |
| “ | 64 | 15 | 6 | 1 in 15 | 12 | 24 |
| “ | 78 | 12 | 6 | 1 in 18 | 12 | 15 |
| “ | 40 | 12 | 6 | 1 in 24 | 12 | 15 |
| “ | 50 | 14 | 6 | 1 in 18 | 12 | 40 |
| Rhyl District | 119 | 9 | 3 | 1 in 18 | 10 | 12 |
| Warrington W. W. | — | — | — | — | 3 | — |
One of the recent dams of the Croton supply, made of concrete, is thirty-one feet at the base, eight and one-half feet at top, six hundred and seventy feet long, and seventy-eight feet high. The main embankment, which forms Lough Vartry of the Dublin Water-Works, is sixty-six feet high at its deepest part, and the greatest depth of water, sixty feet. It is 1,640 feet long on the top, and twenty-eight feet wide, which forms a public road. The base, at the deepest part, is 380 feet wide; the inner slope being 3 to 1, and the outer slope 2½ to 1, and the total quantity of earthwork in it is 320,000 cubic yards. The puddle wall in the embankment is six feet wide at the top (one foot below the top bank), and eighteen feet wide at the level of the old river bed. It was carried, for its entire length, down into solid rock.
The dam of Bradlee basin, Boston, is 2,000 feet in length, twenty feet wide on top, one hundred and fifty feet at the base, and greatest height thirty-five feet. In the center of the bank is a puddle wall ten feet thick at the base, and four feet at the top, founded on the rock. The earth embankment was laid in layers, well watered and rolled.
COMPARISON OF LARGE GRAVITATION WORKS.
| DISTANCE | NO. ACRES | CAPACITY | HEIGHT OF | CAPACITY OF | ||
| OF SRCE | OF WATER | OF STORAGE. | SRCE ABOVE | AQUEDUCT | POPULA- | |
| IN | SHED. | IN GALLONS. | CITY DATUM | IN GALLONS. | TION. | |
| MILES. | IN FEET. | |||||
| New York | 40 | 216,844 | 9 billions | 160 | 92 millions | 1,216,500 |
| Boston | 16 | 100,000 | — | 134 | 86 “ | 412,000 |
| Baltimore | 7 | — | 765 millions | 165 | 170 “ | 332,190 |
| Liverpool | — | 10,000 | 4 billions | — | 17 “ | 600,000 |
| Manchester | 18 | 19,390 | 6 “ | 790 | 39 “ | 750,000 |
| Glasgow[1] | 25¾ | 47,800 | 12 “ | — | 50 “ | 550,000 |
| Dublin | 21.6 | 14,080 | 2½ “ | 692 | 20 “ | 330,000 |
[1] Gorbals not included.
The dam for diverting the waters of Gunpowder Falls, for supply of Baltimore, is built of rubble and white marble upon solid rock. Thickness at base is sixty-two feet; depth of foundation below original surface is thirteen feet; width of the overflow is three hundred feet. The wings extend into the hill on each side two hundred and fifty-six feet. The height from the extreme foundation to the overflow is twenty-nine feet. The filling of the clay and earth on the inside is forty-five feet at the base.
Liverpool, Eng., designs constructing a masonry dam, at the source of the new supply in Wales, eighty-four feet in height.