SOUTH AMBOY  , a city of Middlesex county, New Jersey, U.S.A., on Raritan Bay at the mouth of the Raritan river, about 27 M . S.W. of New York City . Pop . (1900) 6349 (1700 foreign-born); (191o) 7007 . It is served by the Pennsylvania, the Central of New Jersey, and the Raritan River railways . A railway drawbridge and a traffic bridge across the river connect the city with Perth Amboy . South Amboy is an important point for shipments of coal from the Pennsylvania mines . The Pennsylvania Railroad Company and the Susquehanna Coal Company have coal docks here and the latter has great storage yards . Among the city's industries are the mining of clay and sand, and the manufacture of terra cotta . South Amboy, originally a part of South Amboy township (incorporated in 1798), was laid out in 1835, was incorporated as a borough in 1888, and became a city under a general state law in 1908 .