SNOW-DROP TREE. 281 SNOWY OWL. SNOW-DROP TREE, or Silver-Bell Tree (Haltsiu ti'lntptcra and Halesia diptera). Two shrulw or small trees of the natural order Styra- caceiE, with large and veiny pointed deciduous jpaves, and showy wliite flowers, drooping on slender pedicels in short racemes or clusters from axillary buds of the preceding year. They are beautiful shrubs for cultivation. BrMMER BNOWFLAKE. SNOW-DROP TREE (Halesia tvtrnptera). SNOWELAKE (so called from the color of the flower), Letico- jiim. A genus of nine species of bulbous herbs of the natural order AmarvUidacea?, natives of the iledi- terranean region. The spring snowflake ( Leu- cojum vernum) , the best known species, produces umbels of sweet- scented flowers in JIareh or April. The summer snowflake (Le.ucojum wstivum) is a beautiful rapidly growing and freely spreading plant. Leu- cojinn autumniile, a Portuguese species, produces drooping flowers in autumn. These plants make the best growth on rich sandy or loamy soils. Projjagation is by oflscts, obtained as soon as the leaves have become dry. SNOWFLOWER. See Fringe-Tree. SNOW-GOOSE. An Arctic goose (Clien Tiy- fdhorvd] seen in the United States during its migrations, sometimes in vast numbers. It is pure white, except the black wing-quills, washed on the head with reddish ; the beak, which is strongly 'toothed,' is pink and the feet red- dish. An adult male measures 27 inches long, and weighs ."514 pounds. Ross's snow-goose {Chen Rossi) is a miniature of the other, and is known all over the Hudson Bay country as 'horned wavey.' Consult Cones, Birds of the yiirthiii'.'if (Washington, 1874). SNOW-LEOPARD. The ounce (q.v.). SNOW LINE. The level on a mountain slope above which snow exists all the year roimd, or at least very nearly so. The height of this line above sea-level varies greatly both from year to year, and in different localities: it moves up and down within a broad zone, and is deter- mined principally by the temperature, moisture. and avera'ge velocity of the prevailing winds. The average height of the snow line varies from 18.400 feet in the tropical .Vndes, and 10,000 feet in the Himalayas, down to (iOOO feet in Patagonia, and 2000 feet in (Trccnland. See S.NOW : JIoiNTAiN: and the articles on the sepa- rate mountain ranges, as Alps, Himalaya, etc. SNOW-ON-THE-MOUNTAIN. A euphor- biaceuus plant. See Spirge. SNOW-PLOW. A machine for clearing roads and railways of snow. The rotary steam snow shovel has been adopted by all the transcon- tinental lines of the United States and Canada. It consists of a wheel feet in diameter set in a round casing with a flaring front 10 feet square which feeds the snow into the wheel. The wheel contains an inner and outer series of knives piv- oted on radial pins, with their surfaces inclined to one another; when they encounter any snow, they are canted, or set so as to slice it off and feed it into the machine. Behind the knives is a fan wheel composed of a number of radial blades. When the wheel revolves the centrif- ugal force throws the snow- • to the outside of the wheel, where it meets the inclosing case, and is forced through an opening just behind the headlight. A hood to this opening regulates the direction in which the snow is thrown. The weight of the machine is about twenty tons. SNOW-SHOEING. The original snow-shoe of America was a frame of light wood, made in the shape of a more or less elongated circle, across which were criss-crossed ligatures of leather, with a bow on the top, into which the foot could be slipped. Snow-shoes are of four permanent main varieties. One is long ami narrow and sharp at each end, swelling only slightlj- in the middle, and slightly turned up at the toe. Another has a turned-np entry which meets the snow nearly squarely, and a trailing pointed after end. These are favorite patterns of all the far north ; they are about five feet long and a foot wide in the centre, made of white birch and laced with fine caribou skin webbing, excejjt innnediately under the foot, where there is an open bed-cording of thick raw- hide. A third kind is broader and shorter, with an oval entry at the fore end and a trailing, though shcvter, after end. The fourth set are almost circular, with a stumpy beaver-like trail end. The last two styles are the true 'Monta- gnais' or mountaineers' shoes. In walking, the shoe is slightly raised and carried partly over and ahead of its fellow, and when the step is com- pleted the swell of the centre of the frame of the rear shoe lies close to the inward curve of the hinder part of the leading .shoe. The principal snow-shoe clubs of Canada are those of Jlontreal and Quebec. The time record for snow-shoeing is faster than the ordinary' cross-country runs. The hundred-yard dash is covered in a little over twelve seconds, and the mile in five minutes forty seconds. SNOWY OWL. A large owl {'STyctea nyc- tea) which inhabits the circumpolar region, and appears irregularly in winter in more temperate regions southward, occasionally visiting even the central parts of the United States. It has no 'horns,' is white suffused with reddish brown in .summer, but in winter is pure white. Its habits are similar to those of other large owls (q.v.) ; and in arctic America it feeds mainly upon
