Book II. RAILROADS. 541 



be traced out, liaving regard to the direction of the carriage of articles, or trade to be 

 expected ; and if such trade be both ways in nearly equal quantities, a line as nearly 

 horizontally level as possible should be chosen. If the trade is all in one direction, as is 

 generally the case between mines and navigation, then the most desirable line is one with 

 a gentle gradual descent, such as shall make it not greater labor for the horses employed 

 to draw the loaded waggons down, than the empty ones back ; and this will be found to 

 be the case on a railway descending about one foot vertical in one hundred feet horizontal. 

 Or if the railway and carriages are of the very best construction, the descent vertical may 

 be to the length horizontal, as 1 to 50, where there is little or no upgate loading. In 

 cases between mines and navigations, the descents will often be found greater than could 

 be wished. On a railway on the improved plan, where the descent is more than as 1 to 

 50, six or eight waggons, loaded with thirty or forty hundred weight each, will have such 

 a tendency to run downwards, as would require great labor of one horse to check and 

 regulate, unless that tendency was checked by sledging some of the wheels. On such, 

 and steeper roads, iron slippers are applied, one or more to a gang of waggons, as occa- 

 sion may require. Each slipper being chained to the side of one of the waggons, 

 and, being put under the wheel, forms a sledge. "Where the descent is very great, steep 

 inclined planes, with machinery, may be adopted so as to render the other parts of the 

 railway easy. On such inclined planes the descending loaded waggons being applied to 

 raise the ascending empty, or partly loaded ones, the necessity of sledging the wheels is 

 avoided ; and the labor of the horse greatly reduced and lessened. {Fulton. ) 



3466. In order to obtain the desired levels, gentle descents, or steep inclined planes, and 

 to avoid sharp turns, and circuitous tracks, it will often be found prudent to cross valleys 

 by bridges and embankments ; to cut through ridges of land ; and in very rugged coun-. 

 tries short tunnels may sometimes be necessary. The line of railway being fixed, 

 and the plans and sections by which the same is to be executed and settled ; the 

 ground for the whole must be formed and effectually drained. The breadth of the bed 

 for a single railway should be, in general, four yards j and for a double one six yards, 

 exclusive of the fences, side drains, and ramparts. 



3467. The bed of road being so formed to the proper inclination, and the embankments 

 and works thereof made firm, the surface must be covered with a bed of stones broken 

 small, or good gravel, six inches in thickness or depth. On this bed must be laid the 

 sleepers, or blocks to fasten the rails upon. These should be of stone in all places where 

 it can be obtained in blocks of sufficient size. They should be not less than eight, nor 

 more than twelve inches in thickness ; and of such breadth (circular, square, or trian- 

 gular,) as shall make them 150 lbs. or 200 lbs. weight each. Their shape is not material, 

 so as they have a flat bottom to rest upon, and a small portion of their upper surface level, 

 to form a firm bed for the end of the rails. In the centre of each block should be drilled 

 a hole, an inch and a half diameter, and six inches in depth, to receive an octagonal plug 

 of dry oak, five inches in length ; for it should not reach the bottom of the hole ; nor 

 should it be larger than so as to put in easily, and without much driving ; for if too 

 tight fitted it might when wet burst the stone. These plugs are each to receive an iron 

 spike or large nail, with k flat point and long head, adapted to fit the counter sunk notches 

 in the ends of two rails, and thereby to fasten them down in the proper position, or situ- 

 ation in which they are to lie. 



3468. With regard to the rails., they should be of the stoutest cast-iron, one yard in 

 length each, formed with a flanch on the inner edge, about two inches and a half high at 

 the ends, and three and a half in the centre ; and shaped in the best manner to give 

 strength to the rails, and keep the wheels in their track. The soles of the rails, 

 for general purposes, should not, he thinks, be less than four inches broad; and the 

 thickness proportioned to the work they are intended for. On railways for heavy 

 burdens, great use, and long duration, the rails should be very stout, weighing 40 lbs., 

 or in some cases, nearly half an hundred weight each. For railways of less conse- 

 quence, less weight of metal will do ; but it will not be prudent to use them of less 

 than SO lbs. weight each, in any situation exposed to breakage above ground. But 

 it is observed that in mines, and other works under ground, where very small car- 

 riages only can be employed, very light rails are used, forming what are called tram- 

 roads, on a system introduced by Carr ; and these kinds of light railways have been 

 much used above ground in Shropshire, and other counties where coals and other 

 minerals are obtained. 



3469. Infixing the blocks and rails, great attention is required to make them firm. 

 No earth or soft materials should be used between the blocks and the bed of small 

 stones or gravel, on which the rails must all be fixed by an iron gauge, to keep the 

 sides at a regular distance, or parallel to each other. The best width of road for general 

 purposes, is four feet two inches between the flanches of the rails ; the wheels of the 

 carriages running in tracks about four feet six inches asunder. Rails of particular 



