river in central Asia, flowing from NW China northwestward into the Ob: c. 1,850 mi (2,977 km)
also sp. Ir·tish′
A river of northwest China, eastern Kazakhstan, and central Russia flowing about 4,250 km (2,650 mi) generally northwest to the Ob River.
- The double river-systems of the Volga and Kama, the Ob and Irtysh, the Angara and Yenisei, the Lena and Vitim on the Arctic slope, and the Amur and Sungari on the Pacific slope, are instances.
- Chelyabinsk was linked by a transverse line with the middle Urals railway, which connects Perm, the head of navigation in the Volga basin, with Tyumen, the head of navigation on the Ob and Irtysh, passing through Ekaterinburg and other mining centres of the middle Urals.
- By a line running from the sources of the river Ural to the Tarbagatai range (thus separating the steppes of the Irtysh basin from those of the Aral and Balkash basins), thence along the Chinese frontier as far as the S.E.
- This wide area is naturally subdivided into West Siberia (basins of the Ob and the Irtysh) and East Siberia (the remainder of the region).
- Aral-Caspian depression to the lowlands of the Tobol, Irtysh and Ob, and thence towards the lower parts of the Yenisei and the Lena.