a township of Middlesex county in E. Massachusetts, U.S.A. Pop. (1890) 5629; (1900) 8603, of whom 2387 were foreign-born; (1906, estimate) 9881. Area, 52 sq. m. It is served by the Boston & Maine railway. It has pleasant residential villages (Arlington, Arlington Heights, &c.) with attractive environs, and there is an excellent public library (the Robbins library). At Arlington Heights there are several wellknown sanatoriums. Spy Pond (about loo acres) is one of the prettiest bodies of water in the vicinity of Boston. Arlington is an important centre for market-gardening (in hot-houses), and along Mill Brook, in the township, are several factories, including chrome works, a large mill and a manufactory of pianoforte cases. In 1762 Arlington was made a "precinct" of Cambridge (of which it was a part from 1635 to 1807) under the name of Menotomy. In 1807 it became a separate township under the name (retained until 1867) of West Cambridge.
See B. and W. R. Cutter, History of the Town of Arlington. .. 163.71879 (Boston, 1880); and C. S. Parker, The Town of Arlington, Past and Present (Arlington, 1907).