ILKESTON, a market town and municipal borough, in the Ilkeston parliamentary division of Derbyshire, England, 9 m. E.N.E. of Derby, on the Midland and the Great Northern railways. Pop. (1891) 19,744, (1901) 25,384. It is situated on a hill commanding fine views of the Erewash valley. The church of St Mary is Norman and Early English, and has a fine chancel screen dating from the later part of the 13th century. The manufactures of the town are principally hosiery and lace, and various kinds of stoneware. Coal and iron are wrought in the neighbourhood. An alkaline mineral spring, resembling the seltzer water of Germany, was discovered in 1830, and baths were then erected, which, however, were subsequently closed. The town, which is very ancient, being mentioned in Domesday, obtained a grant for a market and fair in 1251, and received its charter of incorporation in 1887. It is governed by a mayor, 6 aldermen and 18 councillors. Area, 2526 acres. ILKLEY, an urban district in the Otley parliamentary division of the West Riding of Yorkshire, England, 16 m. N.W. from Leeds, on the Midland and the North-Eastern railways. Pop. of urban district (1901) 7455. It is beautifully situated in the upper part of the valley of the Wharfe, and owing to the fine scenery of the neighbourhood, and to the bracing air of the high moorlands above the valley, has become a favourite health resort. Here and at Ben Rhydding, 1 m. E., are several hydropathic establishments. The church of All Saints is in the main Decorated, largely restored in 1860. Three ancient sculptured crosses are preserved in the churchyard. The institutions include a museum of local antiquities, a grammar school, the Siemens Convalescent Home and the Ilkley Bath Charitable Institution. The fine remains of Bolton Abbey lie in the Wharfe valley, 5 m. above Ilkley. Ilkley has been identified with the _Olicana_ of Ptolemy, one of the towns of the British tribe of the Brigantes. There was a Roman fort near the present church of All Saints, and the site has yielded inscriptions and other small remains. Numerous relics are preserved in the museum. ILL, a river of Germany, entirely within the imperial territory of Alsace-Lorraine. It rises on a north foothill of the Jura, S.W. of Basel, and flows N.N.E. parallel with the Rhine, which it enters from the left, 9 m. below Strassburg. Its course lies for the most part through low meadowland; and the stream, which is 123 m. long, receives numerous small affluents, which pour out of the short narrow valleys of the Vosges. It is navigable from Ladhof near Colmar to its confluence with the Rhine, a distance of 59 m. It is on this river, and not on the Rhine, that the principal towns of Upper Alsace are situated, e.g. Mülhausen, Colmarl, Schlettstadt and Strassburg. The Ill feeds two important canals, the Rhine-Marne canal and the Rhine-Rhone canal, both starting from the neighbourhood of Strassburg.