HELDER  , a seaport

town at the northern extremity of the province of North Holland, in the kingdom of Holland, 51 M. by rail N.N.W. of Amsterdam . Pop . (1900) 25,842 . It is situated on the Marsdiep, the channel separating the island of Texel from the mainland, and the main entrance to the Zuider Zee, and besides being the terminus of the North Holland canal from Amsterdam, it is an important naval and military station . On the east side of the town, called the Nieuwe Diep, is situated the fine harbour, which formerly served, as Ymuiden now does, as the outer port of Amsterdam . In this neighbourhood are the naval wharves and magazines, wet and dry docks, and the naval cadet school of Holland, the name Willemsoord being given to the whole naval establishment . From Nieuwe Diep to Fort Erfprins on the west side of the town, a distance of about 5 m., stretches the great sea-dike which here takes the place of the dunes . This dike descends at an angle of 40° for a distance of 200 ft. into the sea, and is composed of Norwegian granite and Belgian limestone, strengthened at intervals by projecting jetties of piles and fascines . A circle of forts and batteries defends the town and coast, and there is a permanent garrison of 7000 to 9000 men, while 30,000 men can be accommodated within the lines, and the province flooded from this point . Besides several churches and a synagogue, there are a town hall (1836), a hospital, an orphan asylum, the " palace " of the board of marine, a meteorological observatory, a zoological station and a lighthouse . The industries of the town are sustained by the garrison and marine establishments .