Contractors were requested to annex their bids for one cubic yard of masonry of 27 cubic feet, for each class of masonry, on each side of the river, as follows:

For the erection of the Masonry of the Niagara International Suspension Bridge for Railroad and common Travel.

1. There will be two towers for the support of the wire cables on each side of the river, connected by an arch below. Those on the American side will be about 88 feet; those on the Canadian side 78 feet high. The base of the Towers from the abutments of the bridge will be 28 feet high on the American and 18 feet on the Canadian side, leaving the towers 60 feet high.

This masonry is to be carried up in courses of 18 inches high, each course to be laid down with headers and stretchers alternately, as marked in the plan. The beds or stretchers to be no less than 2 feet wide, the length of headers to be no less than 5 feet. The size and courses and the plan of bond as laid down in the drawings cannot be departed from except with the express permission of the engineer. The face of the outside stone may be left rough as they come from the quarry, to form rockface, except under the archway, where they must be scabbled more carefully and uniformly. The beds and joints must be dressed with the tool so as to be perfectly even and true, without however being cut smooth and fine. They must be perfectly parallel and true to the square and straight edge. Joints to be close, not exceeding 81/6 of an inch. Every course must be level on top, but no dressing or levelling (sic) will be permitted upon the wall. None but perfectly sound and solid stone will be permitted to go in this masonry, and every stone must be laid on its natural bed.

The backing is to be composed of scabbled blocks of the same thickness and size as the face stone. The blocks are to be quarried as if intended for cutting, they must be scabbled and axed all around so as to be true to the straight-edge and square, and perfectly out of wind, ready for the cutter's tool. No spalls or small stones, for filling up, will be allowed to go into this backing, except where a smaller one is wanted occasionally to fill up a gap, or to observe a good bond. No joint in the backing to be over 2 1/2 inches wide.

The beds of all stone to be laid in cement mortar, the joint to be grouted at the completion of every course. The batter of this masonry will be one inch per foot rise on all sides, except where it connects with the arch.

The upper or coping course will be formed of 4 facestones on each side, with backing to correspond, the whole top to be perfectly level and true and prepared for the reception of the first course of the masonry of the towers.

These will be 17 feet wide and 15 feet long. The archstones, except at the spring, will be 3 feet Iong, I foot thick, and no less than 2 feet wide, laid so as to break joints. The bed of all the voussoirs to be cut smooth and true to the level. The face of the ring stones will be rustic with a draft of one inch around the edge, the inside face to be dressed in the same manner. At the spring of the arch the voussoirs must connect well with the abutment mnsonry. The face of the spandrils to be coursed as shown in the drawing.

Will be 60 feet 6 inches high including the cast iron saddles on top; 15 feet square at base, and 8 feet square on top. Each tower will be built in 30 courses, the plan for each course, the size of stone and bond, for face as well as backing, is exhibited in the sixth and seventh course, which will follow alternately, the size diminishing with its elevation, to conform to the batter of the column. A special working plan will be made out for every course. No deviation from the plans whatever will be permitted.

The base of each tower is 6 feet high, with plumb face, and will be built up in 3 equal courses. The face stone will have a draft of 11/2 inches wide around the edge, and the inside will be picked coarsely, so as to present a coarse but uniform rustic appearance. The beds and joints must be cut perfectly true and form close joints. The backing to be also cut stone, beds cut true and parallel, but the sides are to be only well scabbled or axed, so as to be square and out of wind, and to form joints not exceeding 2 1/2 inches in width. No small stones whatever will be allowed to go in. Every block for backing must correspond to the size laid down in the plan. The base is formed by courses No. 1, 2, and 3.-The 4th course is only 16 inches thick and forms the base moulding. A separate plan will be given for this course.

The shaft of the tower is built up in 20 courses, numbered from 5 to 24, a little less than 2 feet in thickness. The plan as laid down for the sixth and seventh course will be alternately pursued. The beds and joints of all the facestone must be cut perfectly true, and the backing will be the same as in the base. The quality of the facestone has to be selected with care; it must be solid and sound throughout, of a uniform texture and colour, free from all seams, spots, or blemish. The face of the outside blocks will have a draft cut smooth, 1.2 inches wide, around the edge, and the balance picked fine to present a fine rustic appearance, in contrast to the base, which is rougher.

Separate plans will be given for the upper six courses, composing the neck, capital, and top, and averaging 2 feet in height. The face of these courses will be cut smooth, as also the moulding course between the base and the shaft. The ornaments on the neck and capital will be cut after they are up. -Separate bids are required for the cutting of this ornamental work. The contractor will also be required to hoist the cast iron saddles on the top of the towers and to set them, as will be directed, on a bed of cement mortar.

They are 27 feet long and 5 feet wide on top, sides battering one inch to the foot. The masonry is to be cut stone and rock face, put up in courses of one foot or more, either equal courses throughout, or diminishing from the foundation upwards. The beds to be one half wider than the height of courses. A regular bond of headers and stretcher must be observed. Backing to be composed of good large flat rubble stone, well bedded and bounded. All the stone to be laid in cement mortar, the facestone to be grouted.

The wings-walls commence at a distance of 136 feet 6 inches from the center of abutments. They are connected by a breastwall, which serves as abutment for the adjoining span. The breastwall is 45 feet long on the top, and 5 wide, battering one inch per foot outside, and forming 3 stops of 9 inches wide.

The wings extend 134 feet. For a length of 44 feet they are 3 feet wide on top, and serve as retaining walls to hold the embankment. For the remainder of the distance they serve as anchorwalls for the support of the anchor chains, and are 6 feet wide on top.

The breastwall as well as the wings and anchorwalls are to be built good and strong, coursed or ranged work. No course to be less than I foot in thickness, the courses to be of equal rise or diminishing from the foundation upwards.

The beds and joints of the facestone must be hammer dressed, so as to be out of wind and square, but no tooling is required. The face is to be scabbled to imitate rock face.-A good bond of headers and stretchers must be observed in all the courses on the face as well as the backing. The backing to be composed of good flat stone, corresponding in size to the facestone. No bonders or round stone will be allowed to go in the backing.

The inside of the anchor masonry must be built up of large flat wellshaped and solid backing stone, and a good bond observed throughout, particularly where the pressure of the anchor chains is to be supported. Every stone must be well settled down in its bed of mortar and not to be disturbed again. The pressure of each chain is to be supported by five large, sound, hard, and solid blocks, 5 feet long, 3 feet wide, and no less than 18 inches thick. These are to be bedded on large backing stones, no less than 6 inches by 3 inches by 1 1/2 inch, and in the position indicated in the plan. The beds of the upper blocks are to be cut smooth, also the upper beds of the lower blocks; the sides are to be scabbled and axed, so as to be out of wind and square.

A cast iron plate will be laid upon the cutface for the support of the chain. An opening will be left around the chain, which is to be fitted with cement-grout, as the wall is carried up.

This grouting is not to be included in the bids for masonry, but will be done by the Company's hands or as extra work.

The face of the wing and anchorwalls will have to be neatly pointed when completed.

The whole of these walls are to be covered by a cut stone coping, 3 feet wide and I foot thick, cut with a slope to shed the water and secured by clamps on top.

The putting up of the iron railing is not to be included in the contract for masonry.

Where the anchor chains and cables connect on top of the wall they will be enclosed by large cut stone blocks, for which separate contracts will be made.

In all cases the lowest course of masonry must be commenced upon the solid rock, and the rockbed must be prepared and levelled off for its reception. This labour is to be included in the price of masonry.

No dirt or dust must ever be allowed to collect upon a wall, it must be kept clean at all times.

An abundance of water must also be used to keep the stone moist and thereby facilitating its connection with the cement mortar. This will be particularly enforced in dry weather.

No dressing or cutting of stone will be allowed upon the wall. If a stone is too large and requires recutting, it must be removed from the wall.

More particular directions will be given during the progress of the work by the engineer or the inspector of masonry whom he may appoint.

All the cement used for mortar or grout must be of the best quality of hydraulic cement, it must not have been manufactured more than three months previous to being used, and must be delivered in good tight barrels packed in paper.

The sand to be mixed with the cement must be good clean sharp quarry sand, and be washed if necessary. The usual proportion of mortar will be one part of cement and two parts of sand, unless directed otherwise. Cement mortar shall not be prepared sooner than one hour at most before it is sea, and in very dry and warm weather it must be kept moist and worked all the time until it is used. No mortar which has stood over one hour, or has been left over night, shall be used, it must be removed. Grout is to be used immediately on being prepared.

In case the contractor shall not, in the opinion of the engineer, well and truly from time to time comply with and perform all the conditions herein stated, the said engineer, at his discretion, may dismiss him from the work, and then the agreement between the contractor and the Bridge Companies shall become null and void, and all claims for any balance for work done or material provided which would have been due shall have been forfeited, and shall become the right and property of the Bridge Companies as damages for breach of contract. Or engineer may employ other parties to hasten the completion of the work, or any part of it, whenever in his opinion it shall be requisite to insure the completion of the work within time specified. The contractor shall have no right to let or transfer any part of the work to other parties without the knowledge and consent of the engineer. IJpon notice by the engineer the contractor will be bound to discharge any incompetent mechanic or workman in his employment for improper work or conduct.

The stone for the masonry on the Canadian side must be obtained on that side, and for the masonry on the American side must be obtained on the American side. No stone is to be quarried within a distance of 200 feet above or below the site of the bridge on the banks of the river.

The stone for the American towers and masonry may be obtained from Lockport.

The whole masonry is to be completed within twelve months from the time the contract is signed.

Monthly estimates during the progress of the work will be made by the engineer of work done and materials delivered upon the ground. Eighty per cent. of the full value of this work will then be paid by the Bridge Companies to the contractor in current funds. And when on completion of the whole masonry the work shall have been finally accepted by the engineer, then the Bridge Companies will make a final payment to the contractor, or his accredited agents, for the balances due to him on the several estimates.