Iron ore is found in many parts of the state. The mines of Morris
County in the Highlands are the most productive. Iron ore was smelted
at Shrewsbury in the seventeenth century by Colonel Lewis Morris, and
in many places at the time of the Revolution. The iron industry of the
state was most extensive and successful during the third quarter of the
last century. The greater abundance and richness of western ores has
since made it impossible to operate most of the mines and furnaces
of Warren and Morris counties profitably. The industry has therefore
declined. A few mines are still worked, however, in these two counties.
Very rich zinc mines are located in Sussex County, in the neighborhood
of Franklin Furnace. In the production of zinc this state ranks fifth
among the states of the Union.
[Illustration: Portland cement factories near Phillipsburg]
Granite of good quality is found in the Appalachian and Highland
zones. The quarrying of this material is a rapidly growing industry.
Besides granite the sandstone of the Piedmont Plateau is widely used
for building purposes. Slate is quarried to some extent in Sussex and
Warren counties. Talc, or soapstone, which, ground into powder, is used
in making certain kinds of paper and for other purposes, is found in
Warren County. The production of cement from limestone and shale, found
in the western part of the Highlands near Phillipsburg, has grown to
be a very important industry. This industry and the quarrying of slate
are parts of the great cement and slate industries of the adjacent
section of Pennsylvania, across the Delaware, near Easton, which are
among the most important in the country. The trap rock of the Piedmont
Plateau is used for building purposes, road making, and railroad beds.
Its hardness makes it particularly valuable for macadam roads. In all
parts of the state are found deposits of sand and gravel necessary in
building operations.
The beds of marl found in the Coastal Plain have already been
mentioned. This region also contains very valuable beds of white sand
and fine clay. This sand is used in the making of glass, and has caused
the establishment of many glass factories in the southwestern part
of the state. Molding sand is also found in great quantity. The most
extensive beds of clay are found in Mercer and Middlesex counties. In
the former they are used in the making of pottery and in the latter
in the making of brick, terra cotta, tile, and other clay products.
The enormous industries of Trenton and of Perth Amboy and its vicinity
are due to the presence of these clays. For the finer pottery, clays
brought from other states or countries are used. Much clay is shipped
from this state to other states.
[Illustration: Pottery works, Trenton]
=Manufacturing.=--New Jersey is an important manufacturing state.
In this state the manufacturing industries have been developed in a
remarkable degree by a combination of conditions and causes. Very
early in the history of New Jersey the people of the state were forced
by their own needs and the demands of their neighbors to establish
manufacturing, and thus this industry has the advantage of many years
of growth. The state is rich in certain important natural resources,
which have been mentioned. It has profited greatly by its nearness to
the coal and iron fields of Pennsylvania and to the two great cities of
New York and Philadelphia, with their enormous demands for manufactured
products. The number of intelligent and skillful workers in the state
is unusually large. The facilities for rapid transportation, both of
raw materials from all sources and of finished products to all markets,
are unusually abundant. The navigable waters which fringe the state,
and the transcontinental railroad systems with their branches, which
cross it, facilitate shipments to every part of the world.
Among the most important manufactures of New Jersey are refined copper,
silk and silk goods, foundry and machine shop products, petroleum
products, packed meats, woolen and felt goods, wire, leather and
leather goods, electrical machinery, tobacco manufactures, chemicals,
and ships. (See Table II for other manufactures.)
[Illustration: Warping silk, silk mills, Paterson]
[Illustration: Weaving silk, Paterson]
Nearly one sixth of the people of the state are engaged in the
manufacturing industries. Only four states, Massachusetts, Rhode
Island, Connecticut, and New Hampshire, show a larger proportion of
workers engaged in manufacturing. Although New Jersey is forty-fifth in
area and ninth in population, this state is sixth in the total value of
manufactured goods, first in the manufacture of silk and silk goods, in
the smelting and refining of copper, in the manufacture of oil cloth
and linoleum and of sewing machines, second in the manufacture of
chemicals, rubber goods, pottery, terra cotta, and fine clay products,
and of paint and varnish, third in the manufacture of electrical
machinery and supplies, and fourth in the manufacture of soap and gold
and silver articles.