The Wonder Book Of Knowledge Part 3

A Battle Won.

The completion of this herculean task marked an epoch in the history of the world. A gigantic battle against floods and torrents, pestilence and swamps, tropical rivers, jungles and rock-ribbed mountains had been fought--and won! Well worthy a place in the halls of immortal fame are the names of the thousands of st.u.r.dy sons who, with ingenuity, pluck and perseverance never before equaled, succeeded in making a pathway for the nations of the world from ocean to ocean.

This great and daring undertaking, which had for its object the opening up of new trade routes and lines of commerce, annihilating distance and wiping out the width of two continents between New York and Yokohama and making the Atlantic seaboard and the Pacific coast close neighbors, is the climax of man's achievement and the greatest gift to civilization.

It will help in the consummation of man's loftiest dreams of world friendship and world peace.[2] So far, in the use of the ca.n.a.l, over forty per cent of the vessels which have pa.s.sed through it have been engaged in the coastwise trade of the United States--each of them saving about 7,800 miles on each trip. If their average speed be taken at ten knots, they have averaged a saving of over a month at sea on each voyage from coast to coast. Where formerly the round trip of a ten-knot vessel required about fifty-five days' actual steaming, the time at sea for the same trip for the same vessel is now reduced to about twenty-two days.

The ca.n.a.l makes San Francisco nearer to Liverpool by 5,666 miles, a saving of two-fifths of the old journey by Magellan. The distance between San Francisco and Gibraltar has been reduced from 12,571 miles to 7,621 miles, a saving of 4,950 miles, or thirty-nine per cent of the former distance.

From San Francisco to Buenos Aires, via Valparaiso and Magellan, is approximately 7,610 miles, which is shorter than the route through the ca.n.a.l, by which the distance is 8,941 miles. To Rio de Janeiro, the distance via Magellan is 8,609 miles; by the ca.n.a.l 7,885 miles. To Pernambuco, on the eastern promontory of South America, the distance via Magellan is 9,748 miles; via the ca.n.a.l 6,746 miles. To Para the distances via Magellan and via the ca.n.a.l are 10,852 and 5,642 miles, respectively.

From San Francisco to Freetown, on the west coast of middle Africa, the distance by the most practicable route, using the Strait of Magellan, is 11,380 miles. Through the ca.n.a.l and by way of the island of Barbados, the distance is 7,277 miles. The new route is less than two-thirds of the former.

With reference to the trade between the Atlantic coast of the United States and the west coast of South America, New York is nearer to Valparaiso by 3,717 miles by virtue of the ca.n.a.l; to Iquique, one of the great nitrate ports, by 4,139 miles; and to Guayaquil by 7,405 miles.

From New York to Guayaquil the present distance of 2,765 miles is approximately twenty-seven per cent of the former distance--10,270 miles.

[Ill.u.s.tration: FORTY TONS OF DYNAMITE DESTROY THE LAST BARRIER BETWEEN THE OCEANS

The blowing up of Gamboa Dike, the last of the dikes in the Panama Ca.n.a.l. This dike separated the water in the Gatun locks from Gaillard Cut. The removal of the dike by a discharge of forty tons of dynamite, set off by President Wilson, from Washington, was the last stage in the completion of the great waterway. Dredges were put to work immediately widening the channel at Cucaracha slide in Gaillard Cut, so that within a short time the ca.n.a.l was ready for use throughout its entire length.

_Copyright by Underwood & Underwood._]

[Ill.u.s.tration: STEAM SHOVEL AT WORK IN GAILLARD CUT, WITH LARGE ROCK IN MOUTH OF SHOVEL

The great progress made in digging the Panama Ca.n.a.l was largely due to the steam shovels.]

As to the Far East, New York is nearer to Yokohama by 3,768 miles than formerly by way of the Suez Ca.n.a.l, but the latter route is eighteen miles shorter than the Panama route for vessels plying between New York and Hongkong. New York is forty-one miles nearer Manila by Panama than by Suez, and 3,932 miles nearer Sydney by Panama. New York is now, by virtue of the Panama Ca.n.a.l, nearer than Liverpool to Yokohama by 1,880 miles, and nearer than Liverpool to Sydney by 2,424 miles.

When the ship enters the harbor of either of the terminal ports it is boarded by officers of the ca.n.a.l who examine its bill of health and clearance, see that its certificate of ca.n.a.l measurement is properly made out, and ascertain any of the vessel's needs in the matters of fuel, supplies, extra men to handle the lines during the pa.s.sage of the locks, etc. These matters are immediately reported to the Captain of the Port, who gives the necessary orders to insure proper attendance on the vessel's needs and directs its start through the ca.n.a.l whenever it is ready.

In all stages of its transit of the ca.n.a.l the vessel must have on board a government pilot. There is no charge for pilotage on vessels going directly through the ca.n.a.l without stopping to discharge cargo or pa.s.sengers at the terminal ports. The pilot is on board in an advisory capacity and is required to confer with the master of the vessel, giving him the benefit of his knowledge and advice as to the handling of the vessel in the various reaches, but the master, who is best acquainted with the peculiarities of his vessel and her ways of answering the helm, is responsible for the navigation of the vessel, except when she is pa.s.sing through the locks.

The handling of a vessel during its transit of the ca.n.a.l is like the handling of a railway train on its "run." The course is equipped with all requisite signals, facilities for mooring, like sidings, and a system of communication between points along the line, which includes a special telephone system connecting all the important points of control in series.

As soon as the vessel starts on its transit of the ca.n.a.l, the Captain of the Port at the point of entrance telephones its starting to the other stations along the course. As the vessel arrives and departs from each of these points, the fact is telephoned along the line, so that there is exact knowledge at each station all the time of the status of traffic, and complete co-operation from the several points of control.

The transit of the ca.n.a.l requires about ten hours, of which approximately three hours are spent in the locks. In the sea-level channels and Gaillard (formerly "Culebra") Cut the speed of vessels is limited to six knots; through Gatun Lake they may make ten, twelve and fifteen knots, according to the width of the channel. A vessel may clear from the ca.n.a.l port at which it enters and, after pa.s.sing through the last of the locks, put direct to sea without further stop.

The handling of a vessel all through the ca.n.a.l, except in the locks, is essentially the same as its handling through any charted channel where observance of signals, ranges and turns is necessary. The ca.n.a.l channel throughout is very accurately charted, fully equipped with aids to navigation, and governed by explicit rules with which the pilots, of course, are thoroughly familiar.

In the locks, the vessel is under the control of the lock-operating force. As the vessel approaches the locks, the operator in charge at the control house indicates by an electrically operated signal at the outer end of the approach wall if the vessel shall enter the locks and, if so, on which side; or if it shall keep back or moor alongside the approach wall. If everything is ready for the transit of the locks, the vessel approaches the center approach wall, which is a pier extending about a thousand feet from the locks proper, lines are thrown out, and connections are made with the electric towing locomotives on the approach wall.

The vessel then moves forward slowly until it is in the entrance chamber, when lines are thrown out on the other side and connections are made with towing locomotives on the side wall. Six locomotives are used for the larger vessels, three on each wall of the lock chamber. Two keep forward of the vessel, pulling and holding her head to the center of the chamber; two aft, holding the vessel in check; and two slightly forward of amidships, which do most of the towing of the vessel through the chamber. The locomotives are powerful affairs, secured against slipping by the engagement of cogs with a rack running along the center of the track, and equipped with a slip drum and towing windla.s.s, which allow the prompt paying out and taking in of hawser as required. No trouble has been experienced in maintaining absolute control over the vessels.

The water within the lock chamber proper, beyond the entrance chamber, is brought to the level of that in the approach, the gates toward the vessel are opened, the fender chain is lowered, and the locomotives maneuver the vessel into the chamber and bring it to rest. The gates are then closed, the water raised or lowered, as the case may be, to the level of that in the next chamber, the gates at the other end are opened, and the vessel moved forward. Three such steps are made at Gatun, two at Miraflores, and one at Pedro Miguel.

When the vessel has pa.s.sed into the approach chamber at the end of the locks, the lines from the towing locomotives on the side wall are first cast off, then those from the locomotives on the approach wall, and the vessel clears under its own power.

Towing is not ordinarily required in any part of the ca.n.a.l, except in the locks, for steam or motor vessels. Tug service for sailing ships or vessels without motive power is at the rate of $15 per hour. If the channel in the cut has been disturbed by a slide, tugs may be used to handle vessels past the narrow places, but in such cases there is no charge for the service to vessels of less than 15,000 gross tonnage.

What is a Geyser?

The famous geyser shown in the ill.u.s.tration is called "Old Faithful"

because of the clock-like regularity of its eruptions. For over twenty years it has been spouting at average intervals of sixty-five minutes.

Geysers were first observed in Iceland and the name, therefore, comes from that language, being derived from the word "geysa," meaning "to gush" or "rush forth." That is just what they do.

There are really three different kinds of geysers; one which throws up hot water, either continually or, like "Old Faithful," at intervals; one which simply emits steam and no water and one which is a sort of a hot-water cistern.

The "Grand Geyser" at Firehole Basin in Yellowstone Park is the most magnificent natural fountain in the whole world. The "Great Geyser" and the "New Geyser" are the most remarkable ones in Iceland, where there are about a hundred altogether. The basin of the former is about seventy feet in diameter, and at times it throws up a column of hot water to the height of from eighty to two hundred feet in the air.

The hot-lake district of Auckland, New Zealand, is also famous in possessing some of the most remarkable geyser scenery in the world. It was formerly noted for the number of natural terraces containing hot water pools, and its lakes all filled at intervals by boiling geysers and hot springs, but the formation of the country was considerably altered by a disastrous volcanic outbreak in 1886, its beautiful pink and white terraces being destroyed. It still has, however, a circular rocky basin, forty feet in diameter, in which a violent geyser is constantly boiling up to the height of ten to twelve feet, emitting dense clouds of steam. This is one of the natural wonders of the southern hemisphere and is much visited by tourists traveling through New Zealand.

[Ill.u.s.tration: _Photo by Brown Bros._

"OLD FAITHFUL" IN ERUPTION]

What Kind of Dogs are Prairie-Dogs?

Prairie-dogs are not really dogs at all, but a kind of a squirrel called a marmot. As the visitors to city Zoological Parks already know, these animals make little mounds of earth, and a great many of these are found in one locality, which is known as a "dog-town." It is possible to travel for days at a time through country which is dotted over with mounds, every one of which is the home of a pair or more of prairie-dogs. These mounds are usually about eighteen feet apart, and consist of about as much earth as would fill a very large wheelbarrow.

This is thrown up by the prairie-dog when he digs out his subterranean home. His dwelling sometimes has one entrance and sometimes two, and there are many much-traveled paths between the different hillocks, showing that they are very neighborly and sociable with one another.

In choosing a town site, they select one which is covered with short, coa.r.s.e gra.s.s, such as is found especially in fields on high ground and mountain sides, for it is on this gra.s.s and certain roots that the prairie-dogs feed. On the plains of New Mexico, where for miles you will not find a drop of water unless you dig down into the earth for a hundred feet or so, with no rain for several months at a time, there are many very large "dog-towns," and it is, therefore, clear that they are able to live without drinking, obtaining enough moisture for their needs from a heavy fall of dew.

At about the end of October, when the gra.s.s dries up and the ground becomes frozen hard, so that digging is out of the question, the prairie-dog creeps into his burrow, blocking up the opening in order to keep out the cold and make everything snug, and goes to sleep until the following spring, without having had to lay up a store of food, as some animals do, to last him through the long, hard winter months. If he opens up his house again before the end of cold weather, the Indians say it is a sure sign that warmer days are near at hand.

If one approaches very cautiously so as not to be observed, a large "dog-town" presents a very curious sight. A happy, animated scene stretches away as far as the eye can see. Little prairie-dogs are found everywhere, on the top of their mounds, sitting up like squirrels, waving their tails from side to side and yelping to each other, until a most cheerful-sounding concert is produced. If you listen carefully, as you draw nearer, however, you will notice a different tone in the calls of the older and more experienced animals, and that is the warning signal for the whole population to disappear from view into their burrows. Then, if one hides quietly in the background and waits patiently for some time, sentinels will mount up to their posts of observation on top of the mounds and announce that it is safe to come out of their burrows and play about again, as the danger is past.

What is Spontaneous Combustion?

Spontaneous combustion is the burning of a substance or body by the internal development of heat without the application of fire.

It not infrequently takes place among heaps of rags, wool and cotton when sodden with oil; hay and straw when damp or moistened with water; and coal in the bunkers of vessels.

In the first case, the oil rapidly combines with the oxygen of the air, this being accompanied by great heat. In the second case, the heat is produced by a kind of fermentation; and in the third, by the pyrites of the coal rapidly absorbing and combining with the oxygen of the air.

The term is also applied to the extraordinary phenomenon of the human body, which has been told of some people, whereby it is reduced to ashes without the application of fire. It is said to have occurred in the aged and persons that were fat and hard drinkers, but most chemists reject the theory and altogether discredit it.

The Story in the Talking Machine[3]