(1) There shall be two waste pipes, three feetdiameter; six draw-off or service pipes of four feet diameter; each pipe will have a square opening lined with granite for the water passages, and a granite mouth-piece with a curved bell-shaped opening; with a well extending from the floor of the water-passages to the top of the gate-house.

(m) The wells for the waste-pipes will have grooves for the gates cut on the sides throughout their height.

(n) In the centre wall there will be a circular waste well, three feet in diameter, beveled at the top to four feet; the lower part of the well where the waste culvert enters, will be, on one side, right-lined. The top of the well will be nine feet below the floor or coping of the gate-house, and the well will be forty-one feet in height.

(0) A waste weir will be constructed in the wall between the fore bays; it will be eight feet high by six feet wide, and eleven feet six inches long, extending over the waste well.

(p) There will be an opening or well from the waste passage through the coping, two feet six inches by six feet, with grooves on both sides of the waste weir for the flush boards.

(9) There will also be a circular opening over the waste well two feet in diameter.

(7) In all the openings, in the coping, of the pipe-wells and entrances to waste weir and waste well, a recess will be cut to receive a cover or grate.

(s) From the lower part of the waste well, there will be a circular waste culvert of four feet interior diameter, connecting with the culvert or sewer now built.

(t) There will also be a drain of vitrified stone pipe, of six inches interior diameter, with curved elbows, extending from the middle of each of the back bays, to the four feet culvert, with a vertical opening, through a granite block placed in the floor.

(v) Over each of the service-pipes there will be a brick arch which will be filled in with brick work or concrete, after the pipes are laid.

(w) There will be a waste way in the central bank adjacent to the gate-house, six feet wide, two feet deep below the top of the centre bank, with two sets of grooves for flush boards.

(x) The top of all the walls and the space over the waste weir and stair way, will be covered by cut granite coping; that over the walls will be nine inches thick, that over the waste weir will be one foot thick, and that over the stairway will be one foot six inches thick.

(y) All the area of the gate-house not covered with granite, will be paved with brick eight inches deep in two courses. In the central partition, there will be a stair-way with stone steps three feet wide from the coping of the gate-house to the well and stair-way leading to the pipevault.

NORTH GATE-HOUSE.

8. (a) The north gate-house will be located at the north end of the central bank.

(b) It will be seventy-two feet long, forty feet wide, and above the floor of the pavement of the back bays forty-two feet high, with a projection containing the induction gates, twenty-seven by twenty-two feet.

(c) The divisions and arrangements will be similar to those of the south gate-house, so far as relates to distribution and waste-pipes, pipe vaults and communications.

(d) There will be eight lower and four upper gates; two-waste-pipes, and four distribution or service-pipes, of three feet diameter.

(e) The partition between the fore bays will be twenty-two feet wide, and that between the back bays eighteen feet wide. The aqueduct will be built on the north side of the gate-house, and carried through the aforesaid partition to the induction gate chamber.

(f) The induction gate chamber will be twenty-two feet long, eleven feet wide, and thirteen feet deep. The outer walls will be five and a half feet wide.

(g) There will be five gates, five by three feet on each side, communicating with the two divisions of the Reservoir.

(h) From the south end of this gate-chamber there will be a waste weir five feet wide, connecting with a semi-circular waste-well on the south side of the gate-house.

(i) This well will connect with a culvert of four feet interior diameter thirty-four feet long; this last culvert connects with another waste-well four feet square, placed in the centre wall of the gate-house, descending four feet below the level of a culvert placed below the floor of the passage between the back bays, of four feet interior diameter.

(j) This last-named culvert will extend to the waste-drain to be built from the north gate-house.

(k). There will be a waste-gate from the aqueduct to the waste-well, which is placed in the middle partition.

(1) There will be openings in the coping over the aqueduct, and over

the flush boards of the waste-weir; otherwise than herein described, the north gate-house will be arranged and built like the south gate-house.

9. (a) The canals leading from the reservoir basins to the fore bays will be lined with support walls; these walls will extend to the height of the paving on the slopes of the reservoir banks.

(b) The coping will be three feet wide and nine inches thick, the faces of the wall will have a slope of two inches base to one foot vertical, the thickness of the walls will vary according to the height of the banks which they are to support.

(c) Where these walls join the gate-house they will be built up with and in connection with the walls of the gate-house.

(d) The face and support walls of the canals leading from the Reservoir basins to the north gate-house in rock cutting, will be of such extent and of such thickness as the engineer may direct.

10. (a) On the outer sides of the gate-houses there will be pipe vaults, the interior of which will be of the length of the gate-house, and twelve feet wide, with side walls eleven feet high, covered with a semi-circular arch.

(b) From the pipe-vault there will be arches over the pipes to the wall of the gate-houses, and on the other side over the pipes to the foot of the slopes of the outer banks, or to such extent as the engineer may direct.

11. (a) An arched vault will form the entrance to the pipe vaults, with a flight of spiral stone and iron steps, placed in a well of twelve feet interior diameter, tapered at top to eight feet diameter, extending from the top of the arch to the top of the bank, where it will be covered with a sky-light.

(b) There will be two bands of iron three inches wide, and one-eighth of an inch thick, placed in the masonry around the well, made of the best American wrought iron.

(c) The iron stairway will connect with a flight of stone steps leading from the gate-house.

(d) The steps of the stairway will be of cast iron, inserted three and a half inches in the wall; they will be at the ends, thirteen inches, and seven and three-quarter inches wide, and thirty-five inches long, exclusive of projections to receive the bolts; the rims will be one inch square, the tread open, of lozenge work, half an inch thick, cut in small pyramids on the top.

(e) The hand-railing will be of gas-pipe, two inches diameter, threesixteenths of an inch thick, supported by posts at each step, of one and a quarter inch diameter at bottom, and three-quarters of an inch at top, of wrought iron, passing through the gas-gipe by drilled holes, five-eighths of an inch in diameter, having square shoulders to support the railing and the beveled washer, and riveted on the upper side. Each post will go through two steps, a rim or shoulder will be welded on the posts above the upper step to support it, and there will be a screw and nut on the lower side to connect the work. There will be a cast iron pillar between the steps through which the post will pass. The posts will also pass through curved braces of wrought iron thirteen inches, by two and a half by one quarter of an inch, at each step, forming a truss, the holes in the steps and braces will be bored so as to fit the posts, (which must be turned) with not more than one thirty-second part of an inch space.

(g) On the stone steps and landing, the hand-railing will be of the same form, with the posts inserted four inches in the stone, and sealed with sulphur. The couplings of the hand rail will be of wrought iron, of the usual form, projecting not more than one-quarter of an inch from the surface of the rail, with rounded corners.

(h) Detail drawings will show the precise form of the details of the sky-light, and of the stairway, and the quantities of material.

(i) The sky-lights will be formed of an iron frame, of the best cast iron used for such purposes, glazed with the best American plate glass, one inch thick, equal to the specimen at the engineer's office.

(j) The iron frame will be connected to the iron coping by a wrought iron hinge with copper bolt, and it will be furnished with a ring on the side for raising it. The glass will be set with mastic or cement as may be directed by the engineer. The hinge will be bolted to the stone work by three wrought iron bolts, passing through eighteen inches of stone.

(k) The steps of the stairway will be of the best cast iron used for such work; the braces, hand-railing, posts and nuts of the railing and other wrought iron will be of the best American wrought iron, to be subjected to such inspection tests as the engineer may direct.

(1) The iron-work will be of the weight required by the dimensions of the drawings, estimating cast iron at twenty-six-one hundredths of a pound per cubic inch, and wrought iron at two hundred and eighty-one one-thousandths of a pound per cubic inch.

(m) All iron work when finished, will be submitted to the engineer for inspection, after being cleaned, and before being put together, and before being painted.

(n) Ten days will be given the engineer to make the inspection after notice shall have been given him that the whole of the iron work is ready for inspection.

(0) The contractor will furnish means for accurately weighing and testing all iron-work; any injury to articles which do not stand the test required by the engineer, will be borne by the contractor; any straightening or restoring of iron-work bent or injured in testing, which stands the test, will be borne by the party of the first part of this contract, and be paid for on the estimate of the engineer. All of the iron-work will be painted with two coats of paint of such color and composition as the engineer may direct.

(p) The skylight frames will be subjected to the changes of the weather, under the direction of the engineer, for at least three months before they will be accepted, and before the final payment will be made.

12. (a) From the waste-pipes there will be culverts four feet interior diameter, connecting with the waste-drains or carried to such extent as the engineer may direct.

(b) In the pipe vault there will be a drain under the service pipes, from the centre drain, which will be two feet square, with circular openings in the covering of the drain at each pipe, for the insertion of a blow-offpipe, connected with the service pipes.

(c) The floor and coping of this drain will be of blue stone, four inches thick, and three and a half feet wide, the stones to be not less than four feet long, which will be estimated as cut-range masonry.

(d) There will be a manhole two feet square in each of the four feet drains in the pipe-vault with granite coping, connected by clamps, of one-inch square iron, covered with blue stone slate, two inches thick and three feet square; these covers will be estimated as cut-range masonry.

(e) Drain holes four inches square will be made in the drains in the pipe-vault.

(f) Four air pipes of fifteen inches interior diameter, will be placed in the walls of each gate-house and pipe-vault for ventilation, extending from the pipe-vaults to the top of the gate-houses by holes in the coping.

(g) Drain pipe of two inches interior diameter, will extend from the spandrels of the interior arches to the square culverts.

(h) All air and drain pipe will be of the best quality of glazed vitrified stone pipe, equal to the specimens at the engineer's office; they will be laid in the masonry and the joints filled with mortar.