Teheran, the' capital of Persia and of the province of the same name, 70 m. S. of the southern shore of the Caspian Sea. It is situated on an immense gravel deposit which slopes down from the foot of the Elburz mountain (rising to an altitude of 12,600 ft.) 8 or 9 m. N. of the city, and extends for 16 m. to near Shah-abdul-Azim, 51 m. S. of it. Teheran was formerly a kind of polygon about 4 m. in circumference, with a mud wall and towers, a dry ditch and six gates, but in 1869 Nasr-ud-din Shah decided upon enlarging the city; the old wall and towers were demolished, the ditch was filled up and used for building sites, and an enceinte consisting of a ditch and 58 unequal bastions according to Vauban's first system was constructed and completed in 1874. The city then took the shape of an irregular octagon, and its circumference (a line through the salient angles of the bastions) measures 19,596 metres, or 12.18 m. The area within the bastions is about 72 sq. m. There are twelve gates, which are closed from two hours after sunset to an hour before sunrise. According to observations taken in 1895 by British officers in connexion with determining the longitude of Madras, the longitude of Teheran (pillar at the north-western corner of the British legation grounds) is 51° 25' 2.8" E. The latitude of the old telegraph office, which was situated almost due S., is 35° 41' 6.83" N., and its elevation 3810 ft. The northern gates of the city are 282 ft. above the southern ones. Teheran has little to distinguish it in general outward appearance from other cities of the country, though in recent years (since the above-mentioned extension) many broad and straight streets and a number of buildings of western architecture, shops with show windows, electric lamps, cabs, &c., have been introduced. " We are in a city which was born and nurtured in the East, but is beginning to clothe itself at a West-End tailor's " (Curzon). Most of the innovations are to be seen only in the northern part of the town where the Europeans and many well-to-do natives reside. The ark or citadel, situated nearly in the centre of the town, contains the shah 's palace and a number of modern buildings of respectable appearance, for instance the foreign office, the war office, customs, telegraph station, arsenal, &c. Immediately north of the ark are the Maidan Tupkhaneh (Artillery Square), 270 yds. by 120, and the great Maidan i Mashk (Maidan of drill), the military parade ground, 550 yds. by 350. South of the ark are the bazaars, the central arcade and caravanserai built c. 1850 by the prime minister Mirza Taki Khan, commonly known as the amir, and beyond them, as well as on the east and west, are the quarters of the old town, with narrow, crooked and mostly unpaved and unclean streets. Teheran has 62 m. of tramways (single lines) and is connected with Shah-abdul-Azim by a single line of railway of one-metre gauge and 52 m. long (the only railway in Persia). Water is freely supplied to the town by means of about thirty underground canals (kanats), led from the slope of the northern hills and running 5 to 10 m. at considerable depths below the surface. The water supply would be ample for the requirements of the population if it could be regularly and equally distributed; but the supply in the months of October and November is only about one-half of that during March, and much water is lost through open ditches and by leakage. The distribution therefore is irregular: in winter and early spring, when the gardens require very little water from the canals, the supply is too great, and in summer it is too little. It has been calculated that the mean water supply amounts to the enormous quantity of 921,00c gallons per hour all the year round, but that, after deducting the quantity wasted in distribution, irrigation of gardens, filling tanks and baths, watering streets, &c., there remain forty-two gallons per head daily during the month of April, seventeen during July, August and September, and ten during October and November. Even the last quantity would suffice if evenly distributed, but as most of the canals are private property and independent of government or municipal control, the distribution is unequal, and it frequently happens that when some parts of the city have water in abundance others have hardly any. Teheran has many mosques, all of recent date, the finest being the one called Masjed i Sipahsalar, built by Mirza Husain Khan Sipahsalar Azam, who was prime minister for ten years until 1884. It is situated in the new part of the city and adjoining it is the Baharistan palace, once the residence of Sipahsalar, afterwards occupied by the national assembly. Another notable mosque is the Masjed i Shah, completed c. 1840. There are also many colleges and schools, some of them with European teachers, including the " German School " (1907) with a yearly subsidy of £ 2200 from the shah. Before Nasr-ud-din's first voyage to Europe in 1873 only four western states had legations and consulates at Teheran; now twelve states are represented.
The present population of Teheran is about 280,000, including 600 Europeans, 4000 Jews, the same number of Armenians. 200 Zoroastrians, and a garrison of 3000 to 4000. The climate is considered unhealthy, particularly in the summer and early autumn, when typhoid, ague and other fevers are prevalent, but something in the way of sanitation has been effected and there is a distinct improvement. The author of the Zinat el majalis, writing in 1596, states that cholera frequently visited the city, and, the north being shut off by high mountains, the air was hot and evil-smelling and the water unwholesome, in fact the climate was so bad that even the Angel of Death ran away from it. The mean yearly temperature calculated from observations taken for a number of years ending 1902 was 62.6° F., the highest temperature observed was 111 °, the lowest 3°, giving a difference of 108° between extremes. The hottest month is July, with a mean of 85.2°, the coldest January, with a mean of 34.25°. The mean annual rainfall during a period of 15 years ending 31st December 1907, was 10 ins.
In the Jehankusha i Juvaini, a Persian history written in the 13th century, the name of the town is written Tiran, while other works have the name as it is now written, viz. Tehran. The latter spelling is due to Arab influence, old Persian names being frequently Arabicized and sometimes becoming unrecognizable. Two villages in the neighbourhood of Isfahan appear as Tiran in old documents, while in modern revenue accounts and lists they are written Tehran. The Mujem el Buldan, a geographical dictionary written in 1224, describes Teheran as a village 4 m. distant from Rai (Rhages). Pietro della Valle, who passed a night (June 6-7, 1618) at Teheran, writes " Taheran " (perhaps thinking it to be a plural of taher, " the pure "), and Sir Thomas Herbert, who visited it on the 14th of June 1627, calls it " Tyroan," and states that it contained 3000 houses built of sun-dried bricks and had its water supply from a little river which flowed through it in two branches. Almost the whole of the city was destroyed by the Afghans in 1723, and Teheran did not regain any importance until the close of the century when Agha Mahommed Khan, the founder of the Kajar dynasty, made it his capital and residence. Dr Olivier, who visited Teheran in 1796, says, " In spite of Agha Mohammed Khan's efforts to induce people to settle and merchants and manufacturers to establish themselves there, the population of Teheran does not amount to 15,000 souls, including a garrison of 3000." (A. H.-S.)
