Iritis
or IRIDITIS (i-rītis, i-rid-i'tis), an inflammation of the iris, accompanied by vascularity, change in color and appearance, ce, irregularity and immobility of the pupil, with a visible and varying amount of lymph deposited in, on, and round the iris.
IRKUT (ēr'köt), a river of Siberia, in the district of Irkutsk, rising in the mountains of Sayansk, near the frontiers of China, and after a course of 220 miles flowing into the Angara at the town of Irkutsk.
IRKUTSK (ēr'kötsk), a government of Eastern Siberia, separated from China on the S. by the Sayan Mountains, from Transbaikalia on the E. by Lake Baikal, and bounded W. by Yeniseisk, and N. and N. E. by Yakutsk, sk, occupies an area of 287,061 square miles. The country is generally mountainous, but produces rye, barley, oats, and vegetables. The most important river is the Angara or Upper Tunguzka (1,000 miles), which connects Lake Baikal with the river Yenisei. The Lena and its tributary the Vitim are the rivers that come next in size. Gold, iron, and salt figure foremost among the mineral products. Agriculture, cattle breeding, and the transport of goods to and from China are the chief occupations of the people. Pop. about 850,000, consisting of Buriats, Tungus, and Russians. The industries brandy distilleries, with iron foundries and factories for salt, cloth, and pottery. are Irkutsk, the capital, on the Angara, is the best-built town in Siberia. It possesses a cathedral, several churches, a public library, a museum of natural history, etc. Pop. about 70,000, mostly Russians and Buriats. Irkutsk was founded by a Cossack chief, Ivan Pochabof, in 1652, and obtained town rights in 1686. Owing to its position on the great Siberian highway between China and Russia, it is the commercial center of Siberia, especially for the tea trade; the annual value of its trade amounts to IRON AND STEEL about $7,000,000. The Angara constitutes the main highway for goods bound for Kiachta across Lake Baikal, as well as for those coming from Eastern Siberia and China for Russia. The communicathe N. parts of Siberia are carried on by the river Lena. A destructive fire occurred in 1879. IRON AND STEEL. Iron, in chemistry, ferrum, is a metallic tetrad element, symbol Fe. at. wt. 56, sp. gr. of pure iron 7.8. Iron occurs nearly pure or alloyed with nickel in meteorites, but is generally found in combination with oxygen and as a carbonate. It is widely diffused in rocks, and often forms the chief coloring matter of clays and sands.
It also occurs combined with sulphur.
The chief ores used for the manufacture of iron are magnetite, hæmatite, brown oxide, spathic ore and clay ironstone.
The ore is first calcined, to expel the water and carbonic acid and most of the sulphur, and to convert the oxides to peroxide, which prevents the waste of ore is then smelted, with the addition of coke and limestone; the limestone unites ble slag, while the oxide of iron is reduced by the action of the carbon monoxide. The iron thus obtained is called cast or pig iron, and is very impure.
Pure iron is prepared by placing four parts of fine iron wire, cut in pieces, and State Alabama California Quantity (long tons) (long tons) IRON AND STEEL high temperature. Iron is a soft, tough, tenacious, malleable, ductile, white metal, not acted upon by dry air; but it rusts in as Gen. iv: 22. On the sepulchers of the ing a hydrate of the sesquioxide.
Iron is mentioned in the Bible as early as Gen. iv: 22. On the sepulchers of the assumed to be iron. Iron ore is said to bar of metal which, from being blue, is assumed to be iron. Iron ore is said to have been discovered in Mount Ida The exportation of about 1406 в. c. The Romans early iron was prohibited by the British govin Britain 54 B. C. iron was prohibited by the British government in 1354, and in 1483 the importation of such manufactured iron goods as could be made at home was forbidden.
In 1783 Cort obtained a patent for rollhot blast was discovered by Dalton in hot blast was discovered by Dalton in 1827, and the Bessemer process for coniron and steel in 1856. iron and steel in 1856.
Native iron is found in masses or nearly pure, still it contains 1 to 20 per cent. of nickel with traces of cobalt, manganese, tin, copper, chromium, phosphoadmit of direct forging into horseshoes rus, etc. Specimens of ore so pure as to admit of direct forging into horseshoes have been mined at Shepherd's Mountain, in the Iron Mountain district of Missouri. The following table shows the iron ore shipped from the mines of the United States in 1918 and 1919, by States: 1918 Value $
15,334,561 14,683 878,612 23.686 65,900,501 1919 (estimate) Quantity (long tons) 4,837,000 (a) 85,000 (a) Value $
13,203,000 (a) 389,000 (a) 47,837,000 3,121 Georgia 262,003 Maryland 6,070 Michigan
17,587,416 13,088,000 Minnesota
43,263,240 144,706,532 34,593,000 128,789,000 Missouri 71,968 270,337 (a) (a) New Jersey 375,238 1,945,651 331,000 1,593,000 New Mexico 275,266 546,212 (a) (a) New York 899,970 5,802,870 648,000 3,694,000 North Carolina 108,332 604,592 67,000 240.000 Pennsylvania 515,845 982,173 543,000 892,000 Tennessee 408,954 1,184,546 271,000 932,000 Utah 52,722 168,438 (a) (a) North Carolina 400,135 1,365,582 290,000 1,150,000 Wisconsin
1,167,640 3,796,408 782,000 2,859,000 Other States b 502,195 1,365,582 784,000 1,696,000 72,021,202 $244,368,147 56,319,000 $203,274,000 a Included under "Other States." b1918: Colorado, Connecticut, Idaho, Massachusetts, Montana, Nevada, Texas, Washington, and Wyoming; 1919: Same States as in 1918, with California, Maryland, Missouri, New Mexico, and Utah in addition. one part of black oxide of iron in a Hessian crucible, and covering it with a mixture of white sand, lime, and potassium carbonate in the proportions used for glass-making; a cover is then closely applied and the crucible exposed to a very The total stocks of iron ore for 1919 were estimated at 12,986,000 long tons.
The production of iron in most foreign were estimated at 12,986,000 long tons. The production of iron in most foreign the war, and in some countries it was entirely cut off. In 1918 the following IRON AGE countries produced the chief supply, outside of the United States: Cuba, 653,829 metric tons; Newfoundland, 769,821 metric tons; France, 1,671,851 metric tons; United Kingdom, 15,285,083 metric tons; Algeria, 782,047 metric tons.
The imports of iron ore into the United States in 1919 amounted to 476,- 461 long tons, valued at $2,385,689. The exports amounted to 996,569 long tons, valued at $4,308,746. The total production of pig iron in 1919 was about 30,- 646,000 long tons, valued at $809,246,000.
There were exported 321,261 long tons of pig iron, valued at $12,313,183.
There were in Dec. 31, 1919, 262 blast furnaces in operation. There were at the end of 1919 22 open hearth furnaces in the course of construction.
The steel produced in the United States in 1918 amounted to 44,462,432 long tons. Of this 9,376,235 tons were Bessemer steel, 34,459,391 tons were open hearth steel, 115, 112 tons were crucible steel, and 511,693 tons were other steel.
Steel production in other countries in 1918 was as follows: United Kingdom, 9,744,891 metric tons; Germany, 14,875,- 753 metric tons; France, 1,809,771 metric tons; and Canada, 1,717,318 metric tons.