In a mountainous country, like Colorado, the problem is how to reach the important mining camps, regardless of the crookedness and increased length given to the line. The Denver and Rio Grande has been compared to an octopus. This is really a compliment to its engineers. It sucks nutriment from every place where nutriment is to be found. To do this it has been forced to climb mountains, where it was thought locomotives could never climb. In one place, called the Royal Gorge, the difficulties of blasting a road-bed into the side of the mountain were so great that it was thought expedient to carry the track upon a bridge, and this bridge was hung from two rafters, braced against the sides of the gorge. In surveying some parts of the lines the engineers were suspended by ropes from the top of the mountains and made their measurements swinging in mid-air. The problem of location is different in an old-settled country, where the position of the towns as trade-centres has been fixed by natural laws that cannot be overruled. In this case the best thing the engineer can do is to get the easiest gradient possible consistent with the topography of the country, and let the curves take care of themselves; always to strike the important towns, even if the line is made more crooked and longer thereby; to so place the line in these towns as to accommodate the public, and still be able to buy plenty of land; also to locate for under or over, rather than grade crossings. [Illustration: Sections of Snow-sheds.] [Illustration] [Illustration] In all countries, old and new, mountainous and level, the rule should be to keep the level of track well above the surface of the ground, in order to insure good drainage and freedom from snow-drifts. The question of avoidance of obstruction by snow is a very serious one upon the Rocky Mountain lines, and they could not be worked without the device of snow-sheds--another purely American invention. There are said to be six miles of stanchly built snow-sheds on the Canadian Pacific and sixty miles on the Central Pacific Railway. The quantity of snow falling is enormous, sometimes amounting to 250,000 cubic yards, weighing over 100,000 tons, in one slide. It is stated by the engineers of the Canadian Pacific, that the force of the air set in motion by these avalanches has mown down large trees, not struck by the snow itself. Their trunks, from one to two feet in diameter, remain, split as if struck by lightning. * * * * * [Illustration: Snow-sheds, Selkirk Mountains, Canadian Pacific. The winter track under cover; the outer track for summer use.] After the railway line has been finally located, the next duty of the engineers is to prepare the work for letting. Land-plans are made, from which the right of way is secured. From the sections, the quantities are taken out. Plans of bridges and culverts are made; and a careful specification of all the works on the line is drawn up.