Part 4
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 windlass, 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 passed 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 canal, 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.
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What is a Geyser?
The famous geyser shown in the illustration 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.
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, coarse grass, such as is found especially in fields on high ground and mountain sides, for it is on this grass 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 grass 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]
As far back as 1855 inventors were experimenting with talking machines; but nothing practical was accomplished till 1877, when Thomas A. Edison constructed a primitive machine capable of recording and reproducing sounds. In the early Edison phonograph the sound vibrations were registered on a tinfoil-covered cylinder. Busy with other inventions, he postponed developing the idea of a talking machine; and meantime other brains were at work on the problem.
In 1885 Chichester A. Bell (cousin of Alexander Graham Bell, of telephone fame) and Charles Sumner Tainter invented the “graphophone.” This was the first practical and commercially usable talking machine. The experiments and discoveries resulting in the production of the Bell and Tainter graphophone were made in the laboratories of Alexander Graham Bell, near Washington, D. C., and the latter assisted and advised with the inventors, and on his own behalf conducted experiments which were productive of highly important results in the art of recording and reproducing sound.
The Bell and Tainter patent was granted in 1886, and although the subject of much controversy, it has been repeatedly sustained by the United States courts, and in one case (87 F. R. 873) Judge Shipman had to consider all that other inventors had done or attempted to do, and he there decided that Bell and Tainter were the first to make “an actual living invention which the public was able to use.”
This method covered “a method of engraving records of sound, producing records of sound by engraving in a wax-like material which would permit of the handling, using and transporting of the record.” Another United States patent, covering a method of duplicating or copying sound records, was granted to Charles Sumner Tainter in 1886.
Of course the talking machine of to-day is a long way removed from the early Edison and the early Bell and Tainter machines, because many master minds have been working on the problem of developing and maturing the art of sound recording and reproducing, and in perfecting machines to be used in reproducing the sound records after they have been made.
Disk records have taken the place of the old-style cylinder records, the latter being confined for the most part to dictating machines for office use, as the Dictaphone, which has largely displaced the shorthand writer in many business houses.
Since the original Thomas A. Edison patents and the Bell and Tainter patent there have been many thousands granted, but only a few need be referred to as constituting the milestones in the evolution and development of the art and industry.
First in point of time and importance is the Macdonald Spring Motor, the invention of Thomas Hood Macdonald, a prolific inventor and contributor of many valuable improvements to the talking machine art and industry. The Bell and Tainter machine was operated by a storage battery and this was an inconvenient and expensive form of power. To meet this condition the Macdonald Spring Motor was invented and from the start proved a tremendous success. Today most of the clockwork motor talking machines are built upon the principles disclosed in the Macdonald Spring Motor patent.
The next important step was the discovery by Macdonald that a critical speed for the surface of the record must be obtained in order to secure best results, and this wonderful principle in the art of sound recording was protected by United States patent issued to Macdonald covering what is known as the Macdonald Graphophone Grand. This discovery and invention has been largely instrumental in the rapid development of sound recording.
Although Bell and Tainter disclosed a method of recording sound on a flat surface, all of the earlier forms of talking-machine records were what are known as cylindrical, records in a cylindrical form. Later the disc record came into use and is now the most popular form. Relatively very few cylinder records are manufactured at the present time. The process of sound recording, as applied to disc records, is covered by United States patent to J. W. Jones, and marks a further important stage in the development of the art and industry.
In present-day sound recording the operation is briefly as follows: A recording machine is employed on which is mounted a rotating turntable carrying a wax-like disc blank. Suspended above, but in contact with the surface of the blank, is a recording needle or stylus, attached to a diaphragm which, in turn, is connected to an amplifying horn. The horn extends beyond the machine and the singer, band or orchestra is stationed in front of the mouth of this horn. As the singer interprets the song the vibrations set up by the singer’s voice are communicated to the diaphragm by the passage of the sound through the horn. These vibrations, striking upon the diaphragm, set in motion the recording needle or stylus, causing it to move rapidly, and its motion is traced upon the surface of the rotating disc in a line which is known as the sound line. Looked at with the naked eye this line has the appearance of a spiral traced upon the surface of the wax-like blank, but examined under a magnifying glass it shows myriad little indentations or grooves in the wall of the sound line. These indentations correspond to the vibrations imparted to the needle through the diaphragm, and are the recorded sounds made by the singer or band. When the song or selection is finished the surface of the wax-like blank has been covered over with this spiral sound line. The blank has become the “master record,” and the first stage of producing a talking-machine record has been passed. The next step is to secure from this master record a metallic counterpart or shell. This is done by the electro-plating process. When the shell is secured the next step is to provide a matrix which serves as a die or stamp from which to press copies or duplicates of the master record. These copies or duplicates are the talking-machine records which the public ultimately purchases. The matrix or die is placed in a power press and the records pressed from the material used in making the sound records. This material is prepared in a plastic form so that it can be forced under pressure into every line and indentation on the face of the matrix.
The discovery of the art of recording and reproducing sound; the development of that art into a giant industry, and the present-day universal sovereignty of the talking machine are tributes to American inventive genius and American industrial enterprise. The contributions to the art and the improvements in the manufacture of talking machines and talking-machine records from sources outside of the United States have been very unimportant. The industry employs many thousands of people in the manufacture of these instruments and records which afford entertainment, instruction and amusement to the entire world.
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What are Petrified Forests?
In the first place, petrification is the name we give to the animal and vegetable bodies which have, by slow process, been converted into stone. We mean very much the same thing when we refer to “Fossil Forests.”
Although in most instances there are comparatively few traces of its vegetable origin left, coal owes its existence primarily to the vast masses of vegetable matter deposited through the luxuriant growth of plants in former epochs of the earth’s history, and since slowly converted into a petrified state.
Coal fields today present abundant indications of the existence of huge ancient forests, usually in the form of coal formed from the roots of the trees. Several such forests have been uncovered, of which one in Nova Scotia is a good example, remains of trees having been found there, six to eight feet high, one tree even measuring twenty-five feet in height and four feet in diameter.
The remains of a fossil forest have been found in an upright position in France, and in a colliery in England, in a space of about one-quarter of an acre, there have been found the fossilized stumps of seventy-three trees, with roots attached, and broken-off trunks lying about, one of them thirty feet long and all of them turned into coal.
A remarkable group of petrified trees, some of them twelve feet in diameter, exists in California, and another in Yellowstone Park, in which the trees are still erect, though converted into stone. An extraordinary forest of such trees has been found in Arizona, lying over a wide space of ground, some of them six feet in diameter and perfectly preserved.
These trees are rather mineralized than fossilized. They are found in volcanic regions and are supposed to be due to the action of hot water, which carried off the organic material and deposited dissolved silica in its place. In some instances the wood has been converted into solid jasper or has been changed into opal or agate, or filled with chalcedony or crystallized quartz, with beautifully variegated colors.
What Animals are the Best Architects?
Animals of a great many different kinds have helped show man the way, in taking advantage of the opportunities which nature affords him to feed, clothe and protect himself, but one of the smallest of the animal kingdom is probably the cleverest of all--the spider. Spiders have many different kinds of enemies, ranging from man down to the very smallest, but dangerous, insects, and most of their enemies possess enormous advantages over them in either strength or agility, or both combined; enemies with wings, swift in movement and able to retreat where the spider cannot follow them; enemies clad in an impenetrable coat of armor, against which the spider’s weapons are powerless, while the spider’s own body is soft and vulnerable. These handicaps have been met by the spider with a multitude of clever contrivances, and if invention and skill are to be regarded as an index to intellectual development, it should be very significant to realize how far spiders are ahead of our near relatives, the almost human members of the monkey family.
One of the most interesting of the spider race is the “trap-door” spider which inhabits warm countries all over the earth. The “trap-door” spider not only builds a home for herself by digging a deep hole in the ground and lining it with silk to prevent the sides from falling in, but she also adds a neat little door to keep out the rain and other troublesome things. She usually chooses sloping ground for her homestead so that the door, which she fastens at the edge of its highest point by a strong silk-elastic hinge, swings shut of its own weight after being opened. She disguises the entrance to her home in a manner superior to the famous art of concealment practiced by the Indians, by planting moss on the outside of the door--living moss taken from the immediate neighborhood--so that the entrance to her house harmonizes perfectly with its surroundings, its discovery being made more difficult by the fact that in her careful selection of a site for her dwelling she also appears to be influenced by the presence of patches of white lichen which distract the eye.
The male spider does not seem to take any part in designing, constructing or decorating the home and does not even share its occupancy, leaving it to the mother and her family--often forty or more children at a time--and living a vagrant life, camping out in holes and ditches when he is not tramping around over the whole countryside. The mother spider, however, like many other animals, takes excellent charge of her children, and guards them carefully from all harm. At the first sign of a commotion going on outside her front door she is known to invariably assemble her family behind her, out of harm’s way, and then place her back against the swinging door, holding it shut with some of her feet and clinging tightly to the inner walls of her home with the others.
There is one kind of spider which has developed an even more elaborate style of architecture, digging another room and adding an upper side gallery to her main residence, and placing a second door at the junction of the two tunnels. The doors are made to swing back and forth in both directions, and she constructs a handle on the outer one, by which she fastens it open with a few threads attached to any convenient grass stems or little stones, when she expects to come home from a hunting expedition with her arms full. If a dangerous enemy threatens her home she usually retreats to the second room, in the hope that he will decide she is out and depart in search of another victim elsewhere, but if he discovers her secret, she slams the second swinging door in his face. Should she be beaten in the pushing match at that point, she slips into the upper side gallery opening above the door, and her enemy’s presence within the inner room automatically blocks the entrance to her hiding place by holding up the swinging door across its only opening.
The Story of the Motorcycle[4]
Interest in the development of mechanically propelled two-wheel vehicles began soon after the introduction of the bicycle in its first practicable form. Man’s natural dislike for manual labor quickly found objection to the physical effort of bicycle travel, and accordingly sought to devise mechanical means of overcoming it.
The earliest known attempt to construct a two-wheel vehicle which would proceed under its own power was made by W. W. Austin, of Winthrop, Mass., in the year 1868. This crude affair consisted of a small velocipede upon which was mounted a crude coal-burning steam engine. The piston rods of the engine were connected directly with cranks on the rear wheel. The boiler was hung between the two wheels and directly back of the saddle, while the engine cylinders were placed slightly above horizontal just behind the boiler. Despite the crudity of this outfit, Austin claimed that he had traveled some 2,200 miles on this, the “granddaddy” of all motorcycles.