Page:The Selkirk mountains (1912).djvu/211

Rh life. It grows on the surface of the snow, giving it a crimson stain.

Re-entrant—Rocks are spoken of as being at a re-entrant angle when their faces slope inwards from the perpendicular.

Roche Moutonnées—A group of scattered knobs of rock, rounded and smoothed by glacial action; so called from their resemblance to a flock of sheep lying down.

Rock-Fall, Rock-Slide—An accumulation of broken rock fallen from the cliffs above, through disintegration of their masses; often of considerable extent.

Rucksack—The modern mountaineering knapsack.

Schrund—A crack or crevasse in the ice of a glacier.

Scree—Loose, broken shale at the foot of a cliff; slopes of debris fallen from above through disintegration.

Séracs—Fantastic pillars of ice formed on a glacier by the intersection of longitudinal and transverse crevasses where the grade of its rock bed is broken by ledges or steps.

Snow-line—The lowest line of permanent snow on a high mountain.

Snow-Mushrooms—Accumulation of snow in the woods on trees, stumps, etc., resembling giant fungi of the species named. They are seen of great size and variety along the Canadian Pacific Railway through the Selkirks.

Snout—The most advanced part of a dry glacier; corresponds to forefoot.

Snowshed—A roofed construction of heavy timbers, built over the line of railway to protect it from avalanches falling from the mountain sides. There are five different types of shed constructed along the line of the C.P.R., according to the nature of the avalanches that may fall and the amount of resistance required.

Stoneman, Steinman—A pile of rocks roughly laid together, usually on a mountain-peak or ridge, and intended to serve either as a landmark or as a record of a visit; a cairn.

Striae, Striation—Grooves, or scratches cut in rocks or boulder-clay by the action of ice moving down an incline.

Strike—The direction in which the various strata comprising a rock mass lie. Generally spoken of with reference to the cardinal points of the compass.

Summit—The highest point of a mountain or peak. The highest part of a mountain pass. The highest crest of a ridge.

Talus—The mass of rock fragments lying at the base of a mountain cliff, formed by the accumulation of pieces brought down from above by the action of gravity, frost, rain, etc.; equivalent to "scree" or "debris."

Tarn—A small mountain lake.

Till—A stiff clay containing boulders of all sizes up to several tons weight: often smoothed and striated by glacial action.

Timber-line—The highest place on a mountain where trees are.

Tongue—The extreme end of a glacier; corresponds to "forefoot" or "snout."

Trail—A path cut through forest, or built along a mountain slope to render travel on foot or in saddle possible. Corkscrew Trail—A trail climbing steep mountain-slopes in zigzags, to obtain a suitable grade.