Chapter 2

In the channels of which there are three, having an aggregate width of about 650 feet, cribs 46 feet wide up and down stream were sunk. In the deepest water, where the rock was uneven, they covered the whole bottom up to about five feet of the level of the silts, and on top of that isolated cribs, 46 in. X 6 in. and of the necessary height were placed seven feet apart, as shown at C Figs 2 and 3. At other places similar narrow cribs were placed on the rock, as shown at D, Figs 2 and 3. The tops of all were brought to about the same level as the before mentioned sills. The rock bottom was cleaned by divers of all bowlders, gravel, etc. The cribs were built in the usual manner, of 12 in. X 12 in. timber generally hemlock, and carefully fitted to the rock on which they stand. They were fastened to the rock by 1½ in. bolts, five on each side of a crib, driven into pine plugs as mentioned for the sills. The drilling was done by long runners from their tops. The upstream side of the cribs were sheeted with 4 in. tamarack plank.

On top of these sills and cribs there was then placed all across river a platform from 36 to 46 feet wide made up of sawed pine timber 12 in. X 12 in., each piece being securely bolted to its neighbor and to the sills and cribs below. It was also at intervals bolted through to the rock.

On top of the "platform" there was next built a flat dam of the sectional form shown by Fig 1. It was built of 12 in. X 12 in. sawed pine timbers securely bolted at the crossings and to the platform, and sheeted all over with tamarack 10 in. thick and the crest covered with ½ in. boiler plate 3 ft. wide. The whole structure was carefully filled with stone--field stone, or "hard head" generally being used for the purpose.

At this stage of the works, namely, in the fall of 1881 the structure presented somewhat the appearance of a bridge with short spans. The whole river--fortunately low--flowed through the sluices of which there were 113 and also through a bulkhead which had been left alongside of the slide with a water width of 60 ft. These openings had a total sectional area of 4,400 sq. ft., and barely allowed the river to pass, although, of course, somewhat assisted by leakage.

It now only remained, to complete the dam, to close the openings. This was done in a manner that can be readily understood by reference to the cuts. Gates had been constructed with timber 10 in. thick, bolted together. They were hung on strong wooden hinges and, before being closed, laid back on the face of dam as shown at B, Figs. 1, 2, and 3. They were all closed in a short time on the afternoon of 9th November, 1881. To do this it was simply necessary to turn them over, when the strong current through the sluices carried them into their places, as shown at A, Figs. 2 and 3 and by the dotted lines on Fig. 1. The closing was a delicate as well as dangerous operation, but was as successfully done as could be expected. No accident happened further than the displacement of two or three of the gates. The openings thus left were afterward filled up with timber and brushwood. The large opening alongside of the slide was filled up by a crib built above and floated into place.

The design contemplates the filling up with stone and gravel on up-stream side of dam about the triangular space that would be formed by the production of the line of face of flat dam till it struck the rock. Part of that was done from the ice last winter; the balance is being put in this winter.

Observations last summer showed that the calculations as to the raising of the surface of the river were correct. When the depth on the crest was 2.50 feet, the water at the foot of the Longue Sault was found to be 25 in. higher than if no dam existed. The intention was to raise it 24 in.

The timber slide was formed by binding parallel piers about 600 feet long up and down stream, as shown on the map, and 28 ft. apart, with a timber bottom, the top of which at upper end is 3 ft. below the crest of dam. It has the necessary stop logs, with machinery to move them, to control the water. The approach is formed by detached piers, connected by guide booms, extending about half a mile up stream. See map.

Alongside of the south side of the slide a large bulkhead was built, 69 ft. wide, with a clear waterway of 60 ft. It was furnished with stop logs and machinery to handle them. When not further required, it was filled up by a crib as before mentioned.

The following table shows the materials used in the dam and slide, and the cost:

______________________________________________________________________ | | | Stone | Exca- | | | Timber, | Iron, | filling, | vation, | Cost. | | cu. ft. | lb. | cu. yds. | cu. yds.| | +---------+---------+----------+---------+----------+ Temporary works | 134,500 | 92,000 | 11,400 | | $79,000 | | | | | | | Permanent dam | 265,000 | 439,600 | 24,000 | 6,500 | 151,000 | | | | | | | Slide, including | 296,500 | 156,400 | 32,800 | | 102,000 | apparatus | | | | | | +---------+---------+----------+---------+----------+ | | | | | | Total | 696,000 | 687,000 | 68,200 | 6,500 | $332,000 | -----------------+---------+---------+----------+---------+----------+

The above does not include cost of surveys, engineering, or superintendence, which amounted to about ten per cent, of the above sum.

The construction of the dam and slide was ably superintended by Horace Merrill, Esq., late superintendent of the "Ottawa River Improvements," who has built nearly all the slides and other works on the Ottawa to facilitate the passage of its immense timber productions.

The contractors were the well known firm of F.B. McNamee & Co., of Montreal, and the successful completion of the work was in a large degree due to the energy displayed by the working member of that firm--Mr. A.G. Nish, formerly engineer of the Montreal harbor.

THE CANAL

The canal was formed by "fencing in" a portion of the river-bed by an embankment built about a hundred feet out from the north shore and deepening the intervening space where necessary. There are two locks--one placed a little above the foot of the rapid (see map), and the other at the end of the dam. Wooden piers are built at the upper and lower ends--the former being 800 ft. long, and the latter 300 ft; both are about 29 ft. high and 35 ft. wide.

The embankment is built, as shown by the cross section, Fig. 6. On the canal side of it there is a wall of rubble masonry F, laid in hydraulic cement, connecting the two locks, and backed by a puddle wall, E, three feet thick; next the river there is crib work, G, from ten to twenty feet wide and the space between brick-work and puddle filled with earth. The outer slope is protected with riprap, composed of large bowlders. This had to be made very strong to prevent the destruction of the bank by the immense masses of moving ice in spring.

The distance between the locks is 3,300 feet.

In building the embankment the crib-work was first put in and followed by a part (in width) of the earth-bank. From that to the shore temporary cross-dams were built at convenient distances apart and the space pumped out by sections, when the necessary excavation was done, and the walls and embankments completed. The earth was put down in layers of not more than a foot deep at a time, so that the bank, when completed, was solid. The water at site of it varied in depth from 15 feet at lower end to 2 feet at upper.

The locks are 200 ft. long in the clear between the gates, and 45 ft wide in the chamber at the bottom. The walls of the lower one are 29 ft. high, and of the upper one 31 ft They are from 10 to 12 ft thick at the bottom,

The locks are built similar to those on the new Lachine and Welland canals, of the very best cut stone masonry, laid in hydraulic cement. The gates are 24 in. thick, made of solid timber, somewhat similar to those in use on the St. Lawrence canals. They are suspended from anchors at the hollow quoins, and work very easily. The miter sills are made of 26 in. square oak. The bottom of the lower lock iis timbered throughout, but the upper one only at the recesses, the rock there being good.

The rise to be overcome by the two locks is 16 ft., but except in medium water, is not equally distributed. In high water nearly the whole lift is on the upper lock, and in low water the lower one. In the very lowest known stage of the river there will never be less than 9 ft. on the miter sills.

As mentioned at the beginning of this article, four locks were required on the old military canal to accomplish what is now done by two.

The canal was opened in May, 1882, and has been a great success, the only drawback--although slight--being that in high water the current for about three-quarters of a mile above the upper pier, and at what was formerly the Chute a Biondeau, is rather strong. These difficulties can be easily overcome--the former by building an embankment from the pier to Brophy's Island, the latter by removing some of the natural dam of rock which once formed the "Chute."

The following are, in round numbers, the quantities of the principal materials used:

Earth and puddle in embankment ...cub. yds. 148,500 Rock excavation, " 38,000 Riprap, " 6,600 Lock masonry " 14,200 Rubble masonry, " 16,600 Timber in cribs, lock bottoms and gates " 368,000 Wrought and cast iron, lb ................. 173,000 Stone filling cu yds ...................... 45,300 Concrete " 830

The total cost to date has been about $570,000, not including surveys, engineering, etc.

The contractors for the canal, locks, etc., were Messrs. R. P. Cooke & Co., of Brockville, Ont., who have built some large works in the States, and who are now engaged building other extensive works for the Canadian Government. The work here reflects great credit on their skill.

On the enlarged Grenville Canal, now approaching completion, there are five locks, taking the place of the seven small ones built by the Imperial Government. It will be open for navigation all through in the spring of 1884, when steamers somewhat larger than the largest now navigating the St. Lawrence between Montreal and Hamilton can pass up to Ottawa City.--_Engineering News_.

* * * * *

DWELLING HOUSES--HINTS ON BUILDING--"HOME, SWEET HOME."

[Footnote: From a paper read before the Birmingham Architectural Association, Jan 30, 1883]

By WILLIAM HENMAN, A.R.I.B.A.

My intention is to bring to your notice some of the many causes which result in unhealthy dwellings, particularly those of the middle classes of society. The same defects, it is true, are to be found in the palace and the mansion, and also in the artisan's cottage; but in the former cost is not so much a matter of consideration, and in the latter, the requirements and appliances being less, the evils are minimized. It is in the houses of the middle classes, I mean those of a rental at from £50 to £150 per annum, that the evils of careless building and want of sanitary precautions become most apparent. Until recently sanitary science was but little studied, and many things were done a few years since which even the self-interest of a speculative builder would not do nowadays, nor would be permitted to do by the local sanitary authority. Yet houses built in those times are still inhabited, and in many cases sickness and even death are the result. But it is with shame I must confess that, notwithstanding the advance which sanitary science has made, and the excellent appliances to be obtained, many a house is now built, not only by the speculative builder, but designed by professed architects, and in spite of sanitary authorities and their by-laws, which, in important particulars are far from perfect, are unhealthy, and cannot be truly called sweet homes.

Architects and builders have much to contend with. The perverseness of man and the powers of nature at times appear to combine for the express purpose of frustrating their endeavors to attain sanitary perfection. Successfully to combat these opposing forces, two things are above all necessary, viz 1, a more perfect insight into the laws of nature, and a judicious use of serviceable appliances on the part of the architect; and, 2, greater knowledge, care, and trustworthiness on the part of workmen employed. With the first there will be less of that blind following of what has been done before by others, and by the latter the architect who has carefully thought out the details of his sanitary work will be enabled to have his ideas carried out in an intelligent manner. Several cases have come under my notice, where, by reckless carelessness or dense ignorance on the part of workmen, dwellings which might have been sweet and comfortable if the architect's ideas and instructions had been carried out, were in course of time proved to be in an unsanitary condition. The defects, having been covered up out sight, were only made known in some cases after illness or death had attacked members of the household.

In order that we may have thoroughly sweet homes, we must consider the localities in which they are to be situated, and the soil on which they are to rest. It is an admitted fact that certain localities are more generally healthy than others, yet circumstances often beyond their control compel men to live in those less healthy. Something may, in the course of time, be done to improve such districts by planting, subdrainage, and the like. Then, as regards the soil; our earth has been in existence many an age, generation after generation has come and passed away, leaving behind accumulations of matter on its surface, both animal and vegetable, and although natural causes are ever at the work of purification, there is no doubt such accumulations are in many cases highly injurious to health, not only in a general way, but particularly if around, and worse still, under our dwellings. However healthy a district is considered to be, it is never safe to leave the top soil inclosed within the walls of our houses; and in many cases the subsoil should be covered with a layer of cement concrete, and at times with asphalt on the concrete. For if the subsoil be damp, moisture will rise; if it be porous, offensive matter may percolate through. It is my belief that much of the cold dampness felt in so many houses is caused by moisture rising from the ground inclosed _within_ the outer walls. Cellars are in many cases abominations. Up the cellar steps is a favorite means of entrance for sickness and death. Light and air, which are so essential for health and life, are shut out. If cellars are necessary, they should be constructed with damp proof walls and floors; light should be freely admitted; every part must be well ventilated, and, above all, no drain of any description should be taken in. If they be constructed so that water cannot find its way through either walls or floors, where is the necessity of a drain? Surely the floors can be kept clean by the use of so small an amount of water that it would be ridiculous specially to provide a drain.

The next important but oft neglected precaution is to have a good damp course over the _whole_ of the walls, internal as well as external. I know that for the sake of saving a few pounds (most likely that they may be frittered away in senseless, showy features) it often happens, that if even a damp course is provided in the outer walls, it is dispensed with in the interior walls. This can only be done with impunity on really dry ground, but in too many cases damp finds its way up, and, to say the least, disfigures the walls. Here I would pause to ask: What is the primary reason for building houses? I would answer that, in this country at least, it is in order to protect ourselves from wind and weather. After going to great expense and trouble to exclude cold and wet by means of walls and roofs, should we not take as much pains to prevent them using from below and attacking us in a more insidious manner? Various materials may be used as damp courses. Glazed earthenware perforated slabs are perhaps the best, when expense is no object. I generally employ a course of slates, breaking joint with a good bed of cement above and below; it answers well, and is not very expensive. If the ground is irregular, a layer of asphalt is more easily applied. Gas tar and sand are sometimes used, but it deteriorates and cannot be depended upon for any length of time. The damp course should invariably be placed _above_ the level of the ground around the building, and _below_ the ground floor joists. If a basement story is necessary, the outer walls below the ground should be either built hollow, or coated externally with some substance through which wet cannot penetrate. Above the damp course, the walls of our houses must be constructed of materials which will keep out wind and weather. Very porous materials should be avoided, because, even if the wet does not actually find its way through, so much is absorbed during rainy weather that in the process of drying much cold is produced by evaporation. The fact should be constantly remembered, viz., that evaporation causes cold. It can easily be proved by dropping a little ether upon the bulb of a thermometer, when it will be seen how quickly the mercury falls, and the same effect takes place in a less degree by the evaporation of water. Seeing, then, that evaporation from so small a surface can lower temperature so many degrees, consider what must be the effect of evaporation from the extensive surfaces of walls inclosing our houses. This experiment (thermometer with bulb inclosed in linen) enables me as well to illustrate that curious law of nature which necessitates the introduction of a damp course in the walls of our buildings; it is known as capillary or molecular attraction, and breaks through that more powerful law of gravitation, which in a general way compels fluids to find their own level. You will notice that the piece of linen over the bulb of the thermometer, having been first moistened, continues moist, although only its lower end is in water, the latter being drawn up by capillary attraction; or we have here an illustration more to the point: a brick which simply stands with its lower end in water, and you can plainly see how the damp has risen.

From these illustrations you will see how necessary it is that the brick and stone used for outer walls should be as far as possible impervious to wet; but more than that, it is necessary the jointing should be non-absorbent, and the less porous the stone or brick, the better able must the jointing be to keep out wet, for this reason, that when rain is beating against a wall, it either runs down or becomes absorbed. If both brick and mortar, or stone and mortar be porous, it becomes absorbed; if all are non-porous, it runs down until it finds a projection, and then drops off; but if the brick or stone is non-porous, and the mortar porous, the wet runs down the brick or stone until it arrives at the joint, and is then sucked inward. It being almost impossible to obtain materials quite waterproof, suitable for external walls, other means must be employed for keeping our homes dry and comfortable. Well built hollow walls are good. Stone walls, unless very thick, should be lined with brick, a cavity being left between. A material called Hygeian Rock Building Composition has lately been introduced, which will, I believe, be found of great utility, and, if properly applied, should insure a dry house. A cavity of one-half an inch is left between the outer and inner portion of the wall, whether of brick or stone, which, as the building rises, is run in with the material made liquid by heat; and not only is the wall waterproofed thereby, but also greatly strengthened. It may also be used as a damp course.

Good, dry walls are of little use without good roofs, and for a comfortable house the roofs should not only be watertight and weathertight, but also, if I may use the term, heat-tight. There can be no doubt that many houses are cold and chilly, in consequence of the rapid radiation of heat through the thin roofs, if not through thin and badly constructed walls. Under both tiles and slates, but particularly under the latter, there should be some non-conducting substance, such as boarding, or felt, or pugging. Then, in cold weather heat will be retained; in hot weather it will be excluded. Roofs should be of a suitable pitch, so that neither rain nor snow can find its way in in windy weather. Great care must be taken in laying gutters and flats. With them it is important that the boarding should be well laid in narrow widths, and in the direction of the fall; otherwise the boards cockle and form ridges and furrows in which wet will rest, and in time decay the metal.

After having secured a sound waterproof roof, proper provision must be made for conveying therefrom the water which of necessity falls on it in the form of rain. All eaves spouting should be of ample size, and the rain water down pipes should be placed at frequent intervals and of suitable diameter. The outlets from the eaves spouting should not be contracted, although it is advisable to cover them with a wire grating to prevent their becoming choked with dead leaves, otherwise the water will overflow and probably find its way through the walls. All joints to the eaves spouting, and particularly to the rain-water down pipes, should be made watertight, or there is great danger, when they are connected with the soil drains, that sewer gas will escape at the joints and find its way into the house at windows and doors. There should be a siphon trap at the bottom of each down pipe, unless it is employed as a ventilator to the drains, and then the greatest care should be exercised to insure perfect jointings, and that the outlet be well above all windows. Eaves spouting and rain-water down pipes should be periodically examined and cleaned out. They ought to be painted inside as well as out, or else they will quickly decay, and if of iron they will rust, flake off, and become stopped.