Looking northeast from about 30th Street are the railroads, draw bridges, decks, etc. The "loop" (business district) and Lake Michigan are seen in the distance. Land fronting the canal is especially valuable for industrial purposes, because of the opportunity it affords for shipping "goods" by boat on the Great Lakes and on the ocean.
The main business section is seen just to the left of the center. The harbor and outlying residential districts are well shown. Boston harbor (and, indeed, most harbors on the east coast of North America) was originally formed by the subsidence of the land and the "drowning" of stream valleys--thus forming navigable bays.
Drumlins, left when the great ice-sheet melted, are seen rising above the waters of the bay. In the Pleistocene epoch (the last geologic epoch before the present time) most of the northern and eastern North America was covered by a great glacier, similar to the one which now covers Greenland.
Tacoma enjoys the national distinction of being the lumber capital of America. It is located on the Commencement Bay of Puget Sound. It is one of the more important seaports of western America. (Excellent photographs may be found in the folder "The Evergreen Playground of Oregon, Washington and British Columbia" put out by Foster Travel Service.)
San Francisco is one of our most important ports. Forty-one modern piers, fifteen miles of berthing space, and 144 miles of spur trackage are required to handle the tremendous cargoes which annually pass through this port. (Pictures of San Francisco may be found in National Geographic--1932, Volume 61, page 400--January-June. Also page 424).
Seattle is one of our most imporant out-ports on the Pacific coast. It is well located for trade with Alaska and the Far East. The annual value of Alaska's commerce alone amounts to about $70,000,000. In addition to its importance as a port, the city has over 500 manufacturing establishments that employ over 110,000 works. (Photographs can be found in the folder put out by Foster Travel Service "The Evergreen Playground".)