SOMMERFELD, an industrial town of Prussia, in the province of Brandenburg, lies on the Lubis, 40 miles to the south-east of Frankfort-on-the-Oder. Its manufactures of woollen cloth are important,—the annual value of the goods produced being upwards of half a million sterling; and it also contains finishing and dye works, an iron foundry, boiler-works, &c. The population in 1885 was 11,364, almost all Protestants.