Of course other factors helped to cause London to become so great, for the city lies at the head of ocean navigation on the Thames, and the Thames estuary faces two other estuaries—those of the Scheldt and the Rhine. In our day the people of London do not think much about the Thames as a barrier. Nevertheless they often have to go out of their way to get across the river, even though there are fourteen passenger bridges, one ferry, and four tunnels. These facilities for ordinary traffic, aside from the railways, cost between thirty and forty million dollars, and the cost of maintaining them and of paying inter est on the original investment is about two million dollars a year. The Thames is still a costly barrier.
Other Cities.—Paris, at the little Isle of Orleans, where the Seine is easily crossed, is another city whose location was originally deter mined by a river acting as a barrier. The city has grown great because it lies near the center of a rich agricultural region known as the Paris Basin. So prosperous a region needs a city of considerable size as its center, but aside from the island which helps to overcome the barrier of the Seine and which at one time served as a stronghold protected by water, there is little reason why the city should be located at one place rather than another. In the same way Cairo is located at a point where the Nile begins to divide into the many branches or distributaries of its delta, and hence where an important ferry is maintained, since it is easier and cheaper to maintain one large ferry than many small ones. Chicago's growth in the first favorable location west of the southern end of Lake Michigan is due to the fact that the lake is a barrier. All the traffic from the North Atlantic States to Wisconsin, Minnesota, and the Dakotas must converge at the lake's southern end, and hence a great railroad center had to grow up there.
The Expense of Water Barriers: New York City.—The city of New York, unlike London and Paris, owes its location not to water barriers, but to the excellent water communication with which it is provided. The very water which affords such good means of com munication with Europe and other far-away places, however, is very troublesome as a hindrance to local communication. This is because New York is built on islands. Manhattan Island and Long Island contain more important parts of the city than the mainland. While the city was small the so-called "rivers" which separate the islands and the mainland caused little trouble, for few people made journeys out of town. In time, however, the lower end of Manhattan became
thickly covered with buildings. Thereupon the price of land began to rise. People who were planning new business enterprises did not want to locate beyond the water barriers, but were willing to pay high prices for land near the center of the city. Accordingly to-day in some parts of New York a single square foot of land is worth over $1000. A piece the size of an ordinary school desk is worth about $5000. From the mere rent of an area the size of five desks the owner could get much more than the average wages of a laborer, or enough to support a family in moderate comfort.
When land became so valuable people began to try to overcome the difficulty due to the water barrier by erecting higher and higher buildings. New York has now more than 200 over fourteen stories high. The lowest of these tower about 200 feet, while the highest, with fifty or more stories, rise 700 feet, and some accommodate about 15,000 workers. The streets between them are like deep canyons, so gloomy that rents in their lower stories have decreased. When the elevators cease to run, as has sometimes happened during a strike, some of the workers are actually unable to climb to their offices, or take half an hour to do it.
While the sky-scraper type of architecture was being developed as one response to the water barrier, a great many ferries were coming into existence as another response. Thus large numbers of people were able to build homes in Brooklyn or on the Jersey side of the Hudson, where land is relatively cheap and the surroundings pleasant. On this account the ferry system grew to such proportions that there are now over forty lines. The railroads, too, except those now known as the New York Central, and the New York, New Haven & Hartford, had to carry their passengers and freight to the city by boat.
In addition to all this the New Yorkers, in their desire to overcome the water barriers of their island home, have built five huge bridges to Brooklyn at the enormous expense of $90,000,000. They have also dug tunnels under the rivers, five to Brooklyn and three to the Jersey side. The cost of the ferries, bridges, and tunnels, by which New York overcomes the water barriers, must have been as much as a billion dollars. Every year the interest on this amounts to $10 for every man, woman, and child in the city. Although the water of New York's harbor is one of the chief causes of the city's greatness, the water between the different parts of the city is a most expensive hindrance.