Feeding the crusher. Field stone drawn in winter. Pile on both sides of crusher. Feed from wagons. Use bins for crushed stone. Screening. Rotary screen. Cost of crushers. Cost of crushing. 193. For economical work, see that there is no interruption in feeding. The maximum amount of stone should be fed; and compel the teams to get it away. The operator should work at night if necessary to keep the crusher and plant in thorough repair, so that the entire outfit of men and teams will not be standing idle while repairs are being made during the day. In setting up the plant, see that it is so arranged that all work will be down-hill; make use of gravity, do not work against it. Build a platform over the crusher for a one-horse dump cart. Gravel can be dumped into a hopper and requires no further handling. 194. Field stone can generally be obtained and piled in winter more cheaply than in summer. 195. If stone is stored for future crushing it should be put in piles on both sides of where the crusher is to be set up. 196. Much can be saved by setting up a crusher so that it can be fed directly from the wagons instead of wheeling the stones in barrows. To permit of this, the crusher may be permanently set in an excavation on a hill side, wagons driving over the crusher; or a platform may be erected to the level of the crusher. 197. The broken stone should be received into bins from the crusher, and from these a wagon containing a quarter of a cord can be loaded in from two to four minutes. Do not keep teams standing at the crusher while the wagon is being filled, instead of using a bin. If a bin cannot be had, extra wagons should be used. Set the bin on a wagon truck for easy moving. 198. By using a rotary screen the crushed stone may be separated into grades according to size. By placing the coarse stone in the bottom of the road, and the finest on top, a smoother and more durable road is obtained. 199. The screen is operated by the power used for the crusher. The mesh of the screen varies; but an ordinary screen has one section with 14-inch perforations; a second with 3-inch perforations, while all larger stone passes out of the end of the screen. The 14-inch mesh makes a good top dressing, the 3-inch mesh provides a good middle course for the road, while the larger grade is put in the bottom of the road. From the screen the broken stone passes to elevated bins, and from these through shutes to the wagons. 200. The cost of crushers varies from time to time, and intending purchasers should communicate with the manufacturers, who can each give their figures. The cost of crusher and screen may be placed at about $1,000 or $1,200, but this is merely an approximation. 201. The cost of crushing varies with many circumstances often from day to day. The wages of men and cost of teams, the hardness of the stone, the size of the stone laid down at the crusher, the degree of fineness to which it is to be broken, the facilities for setting up and feeding, are among the factors which affect the cost. With stone piled at the crusher, and with an engineer, a foreman, two men feeding the crusher, a team hauling to the crusher, two men loading wagons, a man at the bin, and an extra team, an average cost would be 40 cents cubie vard at the crusher. Binding Material. 202. Given a substantial foundation and a suitable surface Use stone material, the stability of a road is largely dependent upon the screenings. bond; that is, upon the filler or binding material and consolidation by rolling. For a crushed stone road, the standard material is stone screenings, consisting of stone-dust, and chips produced in crushing. These are commonly spread over the surface of the broken stone to give a smoother surface and to aid in "packing.' Only a small quantity of the screenings should be used, and these should be well washed down into the coarser stone by a sprinkling cart preceding a heavy roller. This process will bond the material firmly, the stone obtaining a firm mechanical clasp, and the screenings are largely a cementing material to help unite the stones into a water-proof covering. ferior, and is 203. Sand is by no means as useful a bonding material as sand is inare stone screenings. The sand has not the cementing property harmful when that the screenings possess. Sand will aid the road to pack quickly in excess. in dry weather, but in wet weather the weakness of the bond becomes apparent. The sand tends to hold the stones apart rather than aid them to unite strongly together. 204. Gravel which packs quickly is very often imagined by Dirty gravel. roadmakers to be superior to gravel which is cleaner but which packs more slowly. This is a mistake, as gravel that packs quickly, as a rule contains an excess of earth and sand, whereas, it is the stony material that is required on the road. screened 205. Where screened gravel is used in the construction of a Bonding road, it is frequently good practice to use the fine sand and other gravel. screenings taken from the gravel, to put in the bottom of the road. A very slight sprinkling of the screenings may be used over the screened gravel; or a much more satisfactory roadbed will be produced if sufficient stone screenings are obtained from a quarry by rail or otherwise, to sprinkle lightly over the surface of the stone sufficiently to bond the material. of their 206. There is a great difference in the bonding value of stone Different stones screenings. The dust of certain limestones will cement and re- and the value cement readily; while others are of a more crystalline and sandy screenings. quality, and the screenings do not unite the stone so firmly, nor do they make the surface so waterproof. Rolling. essential to 207. The road roller is one of the most important of road- Rolling is making implements. Its use tends to greater durability, and con- good work. sequent economy of maintenance. The cost of a road is largely dependent upon the amount of stone and gravel required; and by the use of a roller, the strength of the surface coating can be much increased, the drainage made more prefect, the life of the road lengthened, and in a given period, a much less quantity of stone is required on the road. must form a crust. 208. It is one of the cardinal principles of roadmaking that The metal the metal must form a distinct crust over the natural earth. This is not possible if the broken stone is dropped on a loose mound of earth, and is left for traffic to consolidate. To this end, Finish the work. Further bene (a) Roll the earth sub-soil before putting on the broken stone or gravel. . (b) Roll the broken stone or gravel until it is thoroughly solid. Municipalities which do not roll the earth sub-grade do not get half the benefit of the roller. 209. A roller finishes a road. Ratepayers see only the surface of the road, and however well it may have been otherwise built, if the metal is left loosely on the surface for vehicles to consolidate, the public are inclined to be dissatisfied. By means of a roller newly made roads are at once placed in their best condition for use, and vehicles are not compelled to drive in the edge of the ditches for a season to avoid a mound of loose material in the centre of the road. 210. In addition to forming the stone into a distinct crust, fits of rolling. bonding the stone, and making a more water-proof covering, the sides of a rolled road are not rutted and flattened in such a way as to prevent good surface drainage. Roll the subsoil then the metal. Traffic consolidates metal, mixing with earth. 211. A road should first be properly graded, crowned and drained. The roller should then be used to consolidate this earth sub-soil so that the gravel or stone placed on it will not be forced down into loose earth, but will form a distinct coating. When this foundation is prepared, the metal can be placed over it and rolled and consolidated into a distinct crust. 212. The consolidation of loosely spread stone or gravel by but wastes it, traffic is a slow process, causing much inconvenience to travel, during which the earth or sub-soil becomes mixed with the stone. Earth intermixed with stone prevents the strong mechanical bond which clean metal will assume when the stones are wedged one against the other by a roller. The particles of earth, when wet, have a lubricating influence on the stone, and under the action of wheels, the surface is more readily broken up. Rolling makes a clean hard crust. Roll metal wet. Work of roller. The steepest grade. Depth of stone to roll. 213. By the use of a roller the earth sub-soil can be first thoroughly consolidated. The stone should be placed on this foundation in lavers, and each layer well compacted. In this way a smooth, durable, waterproof coating of stone, free from earthy material, can be laid over a firm foundation. 214. The roller should be preceded by a watering cart, and the material kept thoroughly wet. Otherwise, rolling should be done in wet weather. 215. The amount of rolling which can be done in a day varies according to the quality of the metal used, the kind and amount of binder, the thickness of the layer of stone rolled, the weight and type of roller, the amount of water used in sprinkling the road, the gradient of the road, and the steam pressure. Less rolling is required to solidify the stone, if the earth sub-grade has been well rolled. With broken limestone, rolled by a twelve-ton steam roller, the amount of stone compacted will average between forty and fifty cubic yards in a day of ten hours. 216. The steepest grade on which a steam roller can be used is 1 in 6. A grade of 1 in 14 gives little trouble either up or down. 217. A depth of 4 or 5 inches of stone is better than either greater or less. But to avoid the expense of rolling in two layers, a depth of 6 or 7 inches may be rolled. 218. In loose stones the voids are about 48%. In dry rolled Voids in stone. stone, the voids are reduced to about 40%, and in wet rolled stone to about 33%. The screenings should partially fill these voids. sides. 219. Rolling should commence at the side of the road Commence at approaching the centre gradually. If the roller is first passed over the centre the loose material is crowded out, and the road flattened. The earth foundation should be rolled, and each succeeding layer up to the top dressing. When the latter is put on, the rolling should be continued until the road is thoroughly compact and solid, able to resist, without displacement, the heaviest load passing over it. 220. A horse roller, weighing six or eight tons will do if a Horse rollers. steam roller canont be afforded, but the horse roller is not sufficiently heavy for the best results. It has to be used longer than the steam roller, The feet of the horses, in exerting sufficient strength to move the roller, sink into and disturb the road metal and injure the shape and quality of the roadway, while on hills it is at a disadvantage. 221. Steam rollers are of various weights, ranging from eight Steam rollers. to twenty tons. Rollers of twelve or fifteen tons weight are those generally used by municipalities of Ontario. The cost of horse rollers is usually about $90 per ton, or from $400 to $600 each. Horse rollers are generally so constructed that the weight may be increased by iron castings, so that a roller of five tons may be made to weigh about eight tons. Steam rollers cost about $3,000. For operation, a horse roller, with two teams, will cost $7 per day. A steam roller will cost $10 a day, including interest and depreciation, but will do several times the amount of work done by a horse roller, so that the saving in operation is considerable. Location of Roads. located. 222. Road allowances in Ontario too often follow concession Roads badly and lot lines, without regard to the suitability of these lines for the location of roads. As a result, by unnecessarily crossing swamps, hills and rivers, the expense of making and maintaining the roads is much greater than it otherwise might be. location 223. To change the location of numerous highways in the Pro- A change of vince would do away with many steep hills, expensive cuts and reduces cost. fills, and with a number of bridges. The unsuitability of the soil also, if low-lying, swamp, or composed of vegetable matter, may render advisable a change of location in favor of a course with a firmer and more easily drained sub-soil. hills no longer 224. It is desirable that a road between two places should be Roads around as direct and short as possible. But a road is not necessarily than over hills. shorter because it follows absolutely one pointing of the compass. The line followed by a vehicle, leading up the hills and down into the valleys may be no shorter, nor, perhaps, as short, as a diverging route going around hills and following comparatively level ground. Cut an apple in two and lay one-half of it flat on a table. The distance from one end of the core to the other measured horizontally around is the same as if measured vertically over. Good roads more valuable than square fields. Powers of Stability of slopes depends on drainage. Angle of Repose." Natural form of slope. Dry stone wall 225. Farm owners prefer to have fields of rectangular shape, and there is a disadvantage in having an estate cut into separate sections by diverted highways. It is very much It is very much more in the interest of a property owner to have the roads leading to his farm good and easily maintained, than to have the farm in a compact block, but the roads to it impassable during a portion of the year, and even then expensive to build. 226. Councils are authorized to alter the location of roads by the Municipal Act, in a manner fair to all parties; and it is advisable that this power be judiciously used. Side Slopes. 227. The stability of earth slopes in cuttings and embankments is subject to atmospheric action, especially alternate frost and thaw, and depends largely on drainage. Clay retains water and becomes pasty. Sand, if in a basin of water-holding earth, becomes a quicksand and is completely unstable. A mixture of sand and clay is at times the most difficult case to deal with. Side slopes are generally left too steep. 228. There is a certain "angle of repose" at which the tendency of earth to slip is overcome. This angle varies with different kinds of earth, under various conditions of moisture. Wet clay is troublesome, and an angle of sixteen degrees is sometimes needed to secure it. Well drained clay, however, will rest at an angle of forty-five degrees, or a slope of one to one. With average gravel and compact earth, a slope of one to one is a safe angle, although first-class gravel will retain an almost vertical face for a considerable time. Sand varies greatly, "water sand" being no better than wet clay. Dry sand needs a slope of one and one-half to one. Rules of this description cannot be laid down with complete accuracy, and it is advisable to learn by observation what slope is needed for a particular piece of earthwork. 229. The natural form of an earth slope when in permanent repose is a concave curve, with the flattest portion near the bottom. There is a tendency to leave the slope rather in the opposite form, with an outward curve. Convex, or straight slopes will invariably slip until the natural form is obtained. In cuttings and embankments approaching ten feet in height, care given to proper construction in this regard is always profitable. 230. A dry stone wall at the foot of an embankment or cutting at foot of slope will protect the drain from slipping earth. A coating of sod is one of the best protectors of the slope, for which there should be a few inches of vegetable mould over the surface, and a liberal sowing of grass seed. Drain back of hill. 231. If a wet condition causes the earth to silp, a surface or under-drain back of the hill may be necessary. Hills. Complete each hill in one operation. ance. 232. Hills require special care for construction and maintenThey must always be counted upon as a matter of extra expense. It is usually a mistake to do a little grading and scraping on a hill every year. Instead, each hill should be taken up and |