Boston, 1777, showing how nearly the site was an island; site chosen chiefly for protection against Indians and wolves.

When railroads were invented, they superseded all other land trade routes, and owing to the greater economy, both in the construction and operation of railroads which follow a water grade, their influence has in most cases strengthened existing cities located by water routes. The exceptions to this occur where railroads run contrary to the general topography of the country, as in the Mississippi Valley, the trade routes now running east and west and not, as originally anticipated, north and south; where mountain barriers are overcome by means of tunnels, such, as those under the Alps and the Cascades, and where railroads in process of building have made temporary terminal points, which started cities, as with Worcester and Atlanta.

In manufacturing, the extractive industries locate near raw materials, lumber mills being built near forests, as in Saginaw, Bay City, Minneapolis, and Seattle; iron foundries near iron or coal mines, as in Pittsburg; smelters near gold and silver mines, as in Denver and San Francisco; salt works near salt wells, as in Syracuse, and formerly in Lincoln; oil refineries near oil wells, as in Cleveland; salmon canneries near the. waters where salmon run, as in Portland and Seattle; fruit canneries near orchards, as in Los Angeles and San Jose; beet sugar factories in or near beet sugar fields, as in Saginaw and Bay City. The extractive industries migrate as raw materials are exhausted. Thus the lumber industry has moved from Maine to Michigan, Wisconsin, Minnesota, and finally the Pacific Coast, and the meat-packing industry from New York to Buffalo, Indianapolis, Chicago, and finally

Savannah, 1818. Showing line of fortifications, also rice swamps on either side, which have restrained growth of city to one direction.

DETROIT AS IT WAS August 20th, 1749.

REFERENCE.

A - Commandant's House. B - Guard House and Barracks. C - Powder Magazine. D - Parish Church. E - Priest's House. F - Cemetery. G - Royal Gardens. H - Individual Gardens.

DETROIT RIVER.

Detroit, 1749. Showing old plat and first houses within the fortifications.

Starting point of Pittsburg. Fort at junction of rivers for military reasons.

Kansas City, Omaha, and St. Joseph, near the centre of the corn belt.

Water power, when of sufficient volume and fall and located in a section of natural resources, has created many cities, such as Pall River, Lowell, Minneapolis, Spokane, and Schaffhausen. Also in many cities water power greatly stimulated the early growth, although steam has since supplanted it, as in Providence and Philadelphia. The recent development of electric transmission of water power for long distances is promoting the growth of Buffalo, Los Angeles, Salt Lake City, Portland, Ore., and Seattle.

As industries become more specialized a steady supply of highly trained labor becomes of greater importance, tending to draw them to the larger cities, but opposed to this is the greater danger of strikes in large cities, which creates a slight counter movement towards smaller villages. A further argument for the larger cities is that they furnish a home market for much of the product, and that being located on trade routes low transportation rates are given, the commercial and industrial factors thus reacting on each other. Climate is a factor to be reckoned with in the textile industries, cotton and woolen manufactures being aided by a moist atmosphere. The general tendency of manufacturing seems to be, first, to create many small towns, and later to promote the growth of the larger cities already started by commerce.