176 The National Geographic Magazine 



it was transformed into a ship-floating 

 river. All the Baltic ports of Germany 

 are more or less obstructed by ice in 

 winter, nor do her great North Sea 

 ports always escape this inconvenience ; 

 for this reason Hamburg and Bremen 

 require outports and Bremen must have 

 an outport all the time because the 

 larger vessels cannot ascend to the city. 

 We have no port like that of Valpa- 

 raiso, Chile — a splendid harbor save for 

 the vital defect that the entrance from 

 the sea is so wide that storms invade it 

 and endanger shipping. We have no 

 need for such a splendid example of 

 engineering art as the great breakwater 

 at Cherbourg which without this protec- 

 tion would be a dangerous roadstead. 

 The North American seaboard shows 

 no conspicuous example of the artificial 

 harbor so common in other countries 

 except at Vera Cruz which has just been 

 turned by the labor of years into a good 

 and commodious port. 



TYPES OF HARBORS 



Most of our Atlantic coast is low and 

 presents all the prominent types of nat- 

 ural harbors. We know that large areas 

 of the earth's surface are very slowly 

 subjected to vertical movements, being 

 uplifted above their former level or de- 

 pressed beneath it ; and that these move- 

 ments are best observed along the mar- 

 gins of the sea. We speak, for example, 

 of the uplifting of a part of the coast of 

 Scandinavia, and of the sinking of the 

 coast of New Jersey. In the course of 

 the depression of the coast line the sea 

 invades the valleys, widening and deep- 

 ening them, and turning some of them 

 into deep water harbors which are called 

 Drowned Valley Harbors. When the 

 sea burst over the barrier at the Golden 

 Gate it turned the valley on which San 

 Francisco stands into one of the finest 

 drowned valley harbors in the world. 

 New York is another example of a 

 drowned valley harbor, which, wher- 

 ever found, are among the best natural 



harbors. We see another form of the 

 drowned valley harbor in the fiords of 

 the Maine coast, long, narrow and deep, 

 with this disadvantage that, when their 

 entrances are funnel-shaped, the incom- 

 ing tide rises very rapidly and high so 

 that the difference between mean high 

 and low tide in some of our Maine ports 

 is as much as 20 feet which is an incon- 

 venience to shipping. The difference 

 between mean high and low tide at New 

 York is only a little over 4 feet. 



The barrier harbor is also well repre- 

 sented on our eastern seaboard ; thus 

 we may speak of Boston harbor as be- 

 ing protected from sea storms by the 

 cluster of islands at its mouth ; and of 

 the numerous smaller ports of the south 

 Atlantic coast as sheltered from the 

 ocean by the sand reefs that extend 

 brokenly along the front of our coast 

 from Long Island to Florida. 



River ports such as Philadelphia and 

 New Orleans and ports at the head of 

 deep embayments, as Baltimore, permit 

 ocean vessels to penetrate a considerable 

 distance into the land which is an advan- 

 tage because ocean freights are cheaper 

 than those of the land routes. Balti- 

 more, 140 miles from the sea, is nearer 

 to the Mississippi valley than is New 

 York. 



Our Pacific coast, unlike our eastern 

 seaboard, is high and rocky and has 

 only four fine harbor centers but they 

 are so distributed as to serve adequately 

 all the purposes of our Pacific trade. 

 Puget Sound, one of the most useful of 

 inlets, has scores of miles of shoreline 

 along which the water is so deep that 

 docks might be built anywhere for the 

 largest vessels. The fine river port of 

 Portland supplements the Puget Sound 

 ports in the northern trade, San Fran- 

 cisco is the great central gateway of the 

 Pacific commerce and San Diego, at the 

 extreme southwestern corner of the 

 country, with a landlocked harbor in 

 which the government has been mak- 

 ing great improvements, is nearest to 



