More difficult to set to follow regular line of curves. More difficult to roll, and less likely to obtain uniformity of steel. Tramway Rails.--Tramways on streets or public roads are now universally recognized as important branches of the railway principle. Their smoothness of movement, increased accommodation, and many other advantages as compared with the old road omnibus, render it no longer necessary to call for special advocacy when there is a possibility of their introduction. They occupy a position so thoroughly appreciated 200 by the public that any check on their reasonable use or extension would be considered as detrimental to the interests of the travelling community. As a rule, these tramways are laid down on streets or roads previously constructed for the ordinary road traffic, where all the preliminary work of earth filling, bridges, drainage, etc., has already been accomplished, and there only remains the selection and laying down of the rails or permanent way over which the tram-cars will have to run. The description and weight of permanent way to be adopted will depend largely upon the weight of the cars to be used and the system of motive-power decided upon for the haulage--whether horses, steam, cable, or electricity. As the portion of the streets or public roads along which the tramway has to be laid will, in all probability, have to be occupied and traversed by all kinds of vehicles besides the tram-cars, it is absolutely necessary that the permanent way for the tramway should be of such description as to require the least possible amount of adjustment of fastenings or opening out of the roadway for repairs. Where the entire width of the street, including the space between the tram-rails, is paved with stone setts, the opening out of even a short length for repairs is tedious and costly, and causes considerable obstruction to the street traffic. It is most important, therefore, that the rail and its fastenings should not only be strong enough for its own tram service and the carts and drays which will pass over and across the track in all directions, but it must possess the minimum necessity for disturbance. Figs. 275 to 279 are sketches of a few of the many types which have been brought into use in various places.