Page:The New International Encyclopædia 1st ed. v. 14.djvu/86

* MOUNTAIN. 68 MOUNTAIN ASH. and distributors ol water. In the passage of moisture-charged winds across them, the mois- ture is precipitated as rain or snow. When mountain ranges intersect the course of constant winds and abstract the moisture, they produce a moist country on the windward side, and a comparatively dry and arid one on the U'cward. This is exemplified in the Andes, the precipitous western surface of which has a different aspect from the sloping eastern jjlaiii; and so also the greater supply of moisture on the southern sides of the Himalayas brings the snow-line 3000 feet lower than on the northern side. Above a certain height the moisture falls as snow, and a range of snow-clad summits would form a more effec- tual separatiim between the plains on either side than would the widest ocean, were it not that transverse valleys are of fre<pient occurrence, which open uj) a i)ass, or way of transit, at a level below the snow-line. Hut even these would not prevent the range being an impassable bar- rier if the temperate regions contained as lofty mountains as the tropics. Mountains also show considerable vertical variati(m in their life and climate zones. It is well known that, other things being equal, the air is one degree cooler for every 300 feet of ascent, and also that the rate of pre- cipitation increases upward. At a certain eleva- tion rain gives way to snow. Corresponding to these varying conditions of temperature and moisture is the clistribution of the vegetation, which is commonly in well-defined zones, each zone distinguished by its species from the zones above and below. Near the top of many moun- tains the vegetation ends altogether, and the top of the mountain is barren. Ar.E OF MoiNTAiNS. The age of most folded mountain systems has been determined by the structure of the sediments of known age which compose them, and their relation to other se<li- ments of known age. For instance, the .Ap- palachian system of the Eastern X'nited States, composed mainly of Paleozoic rocks, is much con- torted, while rocks of Mesozoic age rest against this mountain system in relatively umlisturlied layers. Tt is clear that the main uplift of the mountain system followed the depositicm of the Paleozoic rocks, and preceded that of the Meso. zoic rocks. The age of volcanic mountains is de- termined by the relations of the volcanic materi- als of surrounding sedimentary rocks of known age. The mountain systems of the worlil were formed at various times. Some of them have rep- resented areas of weakness where several moun- tain-making movements have occurred, as in the Pyrenees. .Alps. .Tnra. and Himalayas. Others have been cut down by denudation to their very roots, and do not now appear as moimtains. The greatest and loftiest mountains of elevation have for the most part received their greatest uplift in comparatively recent geological times. Consult: Elie de Beaumont, tirr sur Irx ni/K- trnies (Ir mnntnqnrs (Paris. lS.=i2) : Oeikie, Mounldin Arrhitrrtiirr (London. IS77): Reclus, Thr Hislorii of a Mountniii ( Xew York. IS.'^l) : Suess. fhi.i Anililz tirr fCrdr (Leipzig, ISS.")SS) : Reade, Thr Oriqin nf Mounlniii lianfirs (London. ISRT) : ficikie. F.nrtb Srtilpliirr (New York. ISnS) : Davis, I'InisirnI Dcographii (Boston. I8!)S) : Von Lendenfeld. /)iV Hochprbirfie der Erdr (Freiburc ISO!)): Lapparent. I.ri^ons de fj/offraphie p/ii/.iiV/i/c (2d ed.. Paris, 1808). MOUNTAIN, The. The name of a political faction in the French Revolution. See JIo.ma- G.N.MtDS. MOUNTAIN ABTILLERY. Cannon for use in countries where the usual wheeled vehicles cannot go. Sometimes a jointed gun of consider- able weight, as in the case of the English, sonie- linies a single piece gun — designed to be capal)le of being taken wherever troops may be ordered without retarding their movements. Fixed ani- nuinition with metallic cartridge cases is used entirely. In the United States the mountain guns are of two forms: The Ilotchkiss 2-pounder, 1.65 in. calibre, and the Holchkiss 12-pounder, 3 in. calibre. The carriage is of steel. The cartridge consists of three main portions: the cartridge case, the charge, and the projectile. Two types of projectile are used, canister and shell. The canister for the 2-pounder consists of a cylin- drical tin case holding 30 hardened-lead one-ounce bullets with the interstices filled with a matrix of sulphur. The shell is of cast iron, with point percussion fuze. (See Fl"ZE. ) The 2-poimder gun weighs 121 pounds and is capable of penetrat- ing 1.3 inches of steel at the muzzle. The 12- pounder gun weighs 218 pounds and is capable of penetrating 1.4 inches of steel at the muzzle. The English numntain gun. which is of great im- portance in the Indian and colonial service, is a jointed weapon of three pieces, each section weigh- ing 900 pounds, the entire gun and carriage weighing ."JKiO pounds. MOUNTAIN ASH, Rowan Tree, or QriCK- K.N Tkkk tl'iini.s Aiiriiparid : Sorbiis Auctipariii oi many botanists). A very ornamental Euroi)ean tree of the natural order Rosacea". It does not attain a great size: has in general a very straight erect stem: and is distinguished from the other species of Pynis by pinnated glabrous leaves of MOUNTAIN AKH. serrated leaflets, terminated by a single leaflet; coi-jnibs of snniU flowers; and small globose fruit. The wood is valued for its compactness. The inner bark and sapwood have a very peculiar smell. In the superstitions of European peas- ants a twig of rowan tree was supposed to have great elFicacy in searing away evil spirits. The