Southern Indian Ocean in completing the first circumnavigation of the world.
The mean depth of the Indian Ocean is estimated at about 2,300 fathoms, or slightly greater than that of the Atlantic.
The area of land draining into the Indian Ocean is estimated at 6,813,600 square miles, and the annual rainfall on this land is equal to 4,379 cubic miles of water. The rivers flowing from the Asiatic continent are by far the most important, and they carry an immense amount of detrital matter into the Bay of Bengal and Arabian Sea, these forming extensive deposits of blue mud.
The temperature of the surface waters of the Indian Ocean varies much in different parts of the ocean, and at the same place at different times of the year or states of the wind. In tropical regions the temperature usually varies from 70° to 80° F., and the yearly range is only 7° or 8° F.
The temperature of the water at the bottom of the Indian Ocean is very uniform and subject to little, if any, annual variation. In the Bay of Bengal and Arabian Sea temperatures of 33.7° F. 34.2° F. have been recorded at the bottom. The currents of the Indian Ocean are less constant than in the other great oceans, and are largely controlled by the direction and strength of the monsoons. Some of the most characteristic coral atolls and islands are to be found toward the central part of the Indian Ocean, such as the great Maldive group, the Chagos, Diego Garcia, and the Cocos Islands. Christmas Island is an upraised coral formation. St. Paul's, Mauritius, Rodriguez, and others are of volcanic origin, while Madagascar, Ceylon, and Socotra are typical continental islands.
INDIAN RED, a silicate of iron, imported from the Persian Gulf.
INDIAN RESERVATIONS, lands set aside by treaties between the United States and the Indians for the residence of the latter. Up to 1871 these lands were fixed by treaty, but as that to some extent recognized the independence of the Indians all later arrangements have been made by act of Congress. At first the land was given unreservedly to the Indians but since 1887 the policy has been adopted of giving each individual Indian his allotted share of land, making him a citizen. Eventually under this policy the reservations will disappear entirely.
The larger reservations as they existed in 1920 are:
| Arizona | |
| Acres | |
| Navaho | 12,115,283 |
| Hopi | 2,472,230 |
| Fort Apache | 1,681,920 |
| San Carlos | 1,834,240 |
| Minnesota | |
| Red Lake | 543,528 |
| Montana | |
| Crow | 1,836,753 |
| Fort Peck | 1,774,967 |
| Blackfeet | 959,644 |
| New Mexico | |
| Mescalero Apache | 474,240 |
| Zuñi | 315,040 |
| North Dakota | |
| Standing Rock | 1,847,812 |
| Oklahoma | |
| Choctaw | 2,590,043 |
| Wichita | 1,511,576 |
| Chickasaw | 803,108 |
| Oregon | |
| Klamath | 872,186 |
| South Dakota | |
| Cheyenne River | 2,467,926 |
| Pine Ridge | 1,943,121 |
| Rosebud | 1,524,210 |
| California | |
| Mission (28 reserves) | 202,216 |
| Colorado | |
| Fort Hall | 447,940 |
| Washington | |
| Colville | 1,297,009 |
| Yakima | 837,753 |
The total acreage given over to Indian reservations in the United States was in 1920, 48,477,216 acres.
INDIAN SHOT, an ornamental plant of the arrow root family found in most tropical countries. The seeds are round, hard, and black, hence the name of Indian shot applied to the plant.
INDIAN SUMMER, the name given to a period of mild summer weather which generally occurs towards the end of autumn in the United States.
INDIAN TERRITORY, formerly a territory of the United States, now incorporated in the State of Oklahoma. It was a part of the Louisiana Purchase and in 1829 was set apart by Congress for the occupation of Indians east of the Mississippi river. The portion of the territory was taken in 1890 to form a part of Oklahoma Territory. Indian Territory then had an area of 31,246 square miles. It was occupied by the Five Civilized Tribes, the Cherokees, Creeks, Seminoles, Choctaws, and Chickasaws. By various enactments of Congress the territory was divided among the individuals of each tribe. An enrollment of the members of the tribe was begun and completed on June 30, 1907. In 1914 the allotments of land were practically completed. The discovery of oil and gas wells within the territory produced great prosperity among the Indians owning these lands which have been leased for operation. The movement for statehood in the territory began in 1892 and was followed by a Constitutional Convention held in 1905. The preference of the inhabitants of the territory was for separate statehood, but Congress, however, preferred to establish a joint state composed of Oklahoma and Indian Territory. The statehood bill was passed by Congress in June, 1906,
