the name of three large rivers of Asiatic Russia, the tributaries of the Yenisei. The Lower Tunguska, the most northerly of the three, has the longest course. It takes its rise in the northern part of the government of Irkoutsk, and after running parallel to the Lena, takes a westerly course, when it joins the Yenisei near Turuchans. Its course is estimated to be 1000 miles in length. The Middle Tunguska, after a course of between 500 and 600 miles, falls into the Yenisei in lat. 62° N. The Upper Tunguska contains a larger body of water than either of the other two. It originates in the southern part of Lake Baikal, and flows through a broken and rocky channel. It bears the name of Angara in the first part of its course, till after it receives the Ilim, when it is called the Tunguska. It then flows west, and joins the Yenisei in 59° N.