Sometimes to obtain a fine, straight-fibred thread, wool is spun or twisted with cotton and later the cotton is "carbonized" by acid treatment. The reverse process may also be employed. Special note should be made that in twisting threads together the count number of the yarn will be lessened in proportion to the added weight of the thread or threads. Thus two threads of a 40's count twofolded give a 20'S count—written 2/40's. There is, however, an exception to this in spun silk yarn in which a 2/40's yarn (often written 40/2) is a 40's but twofold, i.e., two threads of 8o's are twisted together giving a folded yarn with 4o hanks (each 84o yd.) to the pound. The twisting of varied count numbers is really simple but mystifying to the uninitiated. Thus a io's count twisted with a 40's count does not give an intermediate count num ber (say 25's) but naturally a thicker count than ia's and conse quently a lower count number, viz., 8's count; and this is true in whatever denomination the count may be stated—cotton, linen, woollen, worsted, etc. (A. F. B.) YAROSLAVL, a province of the Russian S.F.S.R., sur rounded by those of Tver, Cherepovetz, Vologda, Kostroma, Ivan ovo-Vosnesensk and Vladimir. Area 31,705 sq.km. Pop (1926) 1,337,717. Thick deposits of boulder clay, remains of the bottom moraine of the ice-cap of the Glacial period, cover the Jurassic clays, and patches of Triassic "variegated marls" outcrop in some places, while Upper Carboniferous limestones crop out only in the north-west and towards the east. Coniferous forest, with firs pre dominating, occupies 39% of the province, and marshes are extensive, especially between the Sheksna and Mologa, and in the Rostov district. Dwarf birch, the Arctic raspberry (Rubus arcti cus) and Linnaea borealis are widespread. The climate is severe,
the rivers being frozen 118 to 183 days per annum, average Jan uary temperature 6.5° F, average July 61.5° F. The prevailing south-west and west winds make the rainfall heavier than in central Russia.
Of the land free from forest and marsh, only 25% is under plough culture, with rye (36.9%), oats (23.4%) and flax Potatoes, barley, grass, vegetables, chicory and herbs are grown, the latter especially in the Rostov district. Meadow and grassland prevail and the province has a flourishing dairy industry, with exports of butter and cheese. In the years 1926-27 a peat fuel electric station was opened at Liapinsk near Yaroslavl. Bog iron ores, copper sulphate and pottery clay are obtained and there are salt and mineral springs.
The principal river is the Volga, which is connected with the Neva by the Mariinsk and Tikhvinsk canals through its tributaries the Sheksna and the Mologa. The Kotorost, flowing from Lake Nero to the Volga, is navigable in spring, and the Kostroma, flow ing along the north-eastern boundary, is a channel for the export of timber and peat fuel. Of the rivers, 39% are available for steam navigation ; the railway net is poor, and good roads are absent, except for the Moscow-Yaroslavl road. Yaroslavl and Rybinsk (q.v.) are the chief towns.
Yaroslavl, the chief town of the above province on the right bank of the Volga, at its confluence with the Kotorost, in 57° 38' N., 39° so' E. Pop. (1933) 167,300. It is a productive centre with textile factories, and tobacco, leather and lacquer industries. Founded in 1026-36, it was the chief town of the principality from 1218 to 1417, when it was annexed by Moscow. The Uspenskiy cathedral was begun in 1215 and rebuilt 1646-48, and there are remains of 15th and 17th century monasteries.