Janesville, capital of Rock county, is on both sides of Rock River, 45 miles S.E. of Madison, at the intersection of the Milwaukie and Mississippi with the Fond du Lac and Rock River Railroad. lAis one of the most important cities in the state, and is built principally on a level plain between the river and the bluffs, which are about 100 feet high. It has several large mills, for which the falls of the river at this point afrord excellent sites. It is the center of an active and increasing trade. It was settled about the year 1836, and incorporated a city in 1853. It has 8 churches, the State Institution for the Blind, and, in 1860, 7,500 inhabitants.