ORTA, LAKE OF, in N. Italy, W. of Lake Maggiore. It has been so named since the 16th century, but was previously called the Lago di San Giulio, the patron of the region—Cusio is a merely poetical name. Its southern end is about 22 m. by rail N.W. of Novara on the main Turin-Milan line, while its north end is about 4 m. by rail S. of the Gravellona-Toce railway station, half-way between Ornavasso and Omegna. It has an area of about 61⁄4 sq. m., it is about 8 m. in length, its greatest depth is 482 ft., and the surface is 951 ft. above sea-level, while its width varies from 1⁄2 to 11⁄4 m. Its scenery is characteristically Italian, while the large island of San Giulio (just W. of the village of Orta) has some very picturesque buildings, and takes its name from the local saint, who lived in the 4th century. The chief place is Orta, built on a peninsula projecting from the east shore of the lake, while Omegna is at its northern extremity. It is supposed that the lake is the remnant of a much larger sheet of water by which originally the waters of the Toce or Tosa flowed south towards Novara. As the glaciers retreated the waters flowing from them sank, and were gradually diverted into Lago Maggiore. This explains why no considerable stream feeds the lake of Orta, while at its north end the Nigoglia torrent flows out of it, but in about 1⁄2 m. it falls into the Strona, which in turn soon joins the Toce or Tosa, a short distance before this river flows into Lago Maggiore.(W. A. B. C.)