Navigation light

“ During an ascension the rise or fall of the vessel may be instantly noted on the dial of the statoscope, the temperature, pressure and moisture of the atmosphere may be read on recording instruments, messages may be sent by tele77graph and telephone either by wire or through space, and sky or landscape may be photographed if there be sufficient light. ”

“ Terms and Definitions Short range aids to navigation are those intended to be used visually or by radar while in inland, harbor and approach, and coastal navigation. The term encompasses lighted and unlighted beacons, ranges, leading lights, buoys, and their associated sound signals. Each short range aid to navigation, commonly referred to as a NAVAID, fits within a system designed to warn the mariner of dangers and direct him toward safe water. An aid’s function determines its color, shape, light characteristic, and sound. ”

“ It is best used during daylight hours and for short distances. (2) Navigator-observer methods. This is the most accurate means of river navigation and can be used effectively in all light conditions. Equipment needed to do this is a compass, photo map (first choice) , topography map (second choice) , poncho (for night use) , and pencil and flashlight (for night use) . (a) The navigator is positioned in the front of the boat and does not paddle. The navigator keeps his map and compass oriented at all times. To check the map during darkness, he uses his flashlight under a poncho. ”

“ The reason for this is that in both cases, either your Variation or Deviation may change and throw you off.
Practically all navigation in strange waters in sight of land and in all waters out of sight of land depends upon the determination of angles. The angle at which a lighthouse is seen from your ship will give you much information that may be absolutely necessary for your safety. The angular altitude of the sun, star or planet does the same. The very heart of Navigation is based upon dealing with angles of all kinds. ”

“ We would not befog our vision of the future with any wild imaginings, seeking, as some have done, to see in the electricity or other hidden power of heaven the means for its subjugation by man; but it is far from unreasonable to hope that but a little while shall pass, and we shall have more perfect and reliable knowledge of the tides and currents in the vast ocean of air, and when that day may have come then it may be claimed that the grand problem of aerial navigation will be already solved. ”

“ The practical value of this science is best appreciated by the navigator, who sees in the sun and moon his clock, and in the stars and planets the ready means of learning his latitude and longitude. It is one of the first tasks of the midshipman to become familiar with the use of the sextant, by which he works out the problem of ascertaining the exact place of the ship upon the ocean. Navigation is helpless without the assistance of astronomy. ”

“ There are no permanent marks on the sea, as there are on the land, by which the navigator can guide his course. Nevertheless, seamen know their path over the trackless ocean with a certainty as unerring as would be possible on shore; and it is all done by the help of astronomy. The navigator's observations of the sun are astronomical observations; the tables he uses in calculating his observations—the tables that tell him just where he is and in what direction he must go—are astronomical tables. Indeed, it is not too much to say that without astronomy there could be no safe ocean navigation. ”

“ The Baker navigating machine, with the chart, was on my knees. Not knowing what kind of weather was before us, I knelt on my seat and made haste to take observations on the sea, the horizon, and the sun, through intervals in the covering of clouds.
The navigation of aircraft, in its present [Pg 43] stage, is distinctly more difficult than the navigation of seacraft. The speed at which they travel and the influence of the wind introduce problems which are not easily solved. ”

“ When their observations, their needs, or their pleasures demanded it, they could descend to within a short distance of the earth, say ninety feet, and fix themselves in their position by means of an anchor. It might, perhaps, be possible, by taking the advantage of favourable winds, to make the tour of the world. “Experience will perhaps demonstrate that aerial navigation presents less inconvenience and less dangers than the navigation of the seas.” ”

“ When the navigator is directly east or west, the altitude, corrected for the time of observation, gives its longitude.
If the horizon is invisible, owing to fogs or unsuitable clouds, it may be replaced by means of a spirit level; but great care should be taken in making such observations, since a spirit level on an aëroplane or airship is not wholly reliable, unless the craft is proceeding in an absolutely straight direction, and without sway of any kind.
All methods of navigation by Astronomical Observation fail when the sky is obscured by clouds and the heavenly bodies cannot be seen. ”

“ In recent years, however, the familiarity with Ocean routes that has been attained; the greatly extended area of coast surveys, and the admirable system of lights and beacons established throughout the navigational zones of the world, have in the course of years caused the work of the Observatories to become of less importance to practical navigation, and more a matter of scientific research. ”

“ The system of laying off the heavens just described is well enough for the momentary locating of a body, which is a very important feature in navigation, but for some purposes a more stable point than the zenith, which on shipboard is ever changing, is needed, from which to form a system that is constant the world over. To meet this demand we take the point in the sky penetrated by the prolongation of the earth’s northern axis—the celestial pole—and from this point meridians and parallels are developed upon the celestial sphere as has been done on the earth. ”

“ Having no sun, moon, nor stars, their navigation is all done by dead reckoning; but they have developed instruments of extreme delicacy that locate land at great distances, accurately indicating this distance and the direction; others that determine speed, mileage, and drift, as well as a depth gauge wherewith they may record soundings anywhere within a radius of a mile from the ship. ”

“ The Lead Line
SINCE the coming of the mariners’ compass many centuries ago, navigation has made steady headway. It is now an exact science, and vessels properly equipped with needed instruments and with men able to use them, can, no matter what the winds or seas, or how extended the voyage, be brought safely to their destination.
The instruments used in navigation are, the compass, by which ship’s courses are steered; the sextant by which observations of the sun, moon and stars are taken, and through which the latitude is ascertained ”

“ The ocean was all right, and so was the patent log; as for speed, one saw it with his own eyes. Therefore the thing that was not all right was the figuring that refused to boost the Snark along over the chart. Not that this happened every day, but that it did happen. And it was perfectly proper and no more than was to be expected from a first attempt at applying a theory.
The acquisition of the knowledge of navigation has a strange effect on the minds of men. The average navigator speaks of navigation with deep respect. ”

“ There are three methods of aërial navigation—"Dead Reckoning," Astronomical Observation, and Directional Wireless Telegraphy. None should be used alone; for although accuracy may be obtained with any single method, it is highly advisable to check each by means of the others.
As in the case of marine navigation, a reliable compass, either of the magnetic or gyroscopic type, is essential for aërial navigation, as well as an accurate and reliable chronometer. Suitable charts must be provided, showing all parts of the route to be covered. ”

“ THERE is a movement of the waters of the ocean which, though it be a translation, yet does not amount to what is known to the mariner as current, for our nautical instruments and the art of navigation have not been brought to that state of perfection which will enable navigators generally to detect as currents the flow to which I allude as drift. ”

“ Thus, you see, the telescope itself may be made to furnish us with many valuable illustrations. We may also turn to good account the lessons to be learned by the study of the stars for the purpose of navigation. The mariner, crossing the trackless sea, by taking astronomical observations, can steer himself with accuracy to his desired haven. ”

“ It has long been our chief reliance for rapid traveling. You find us in this ship; but, although navigation is a perfected science, this mode of traveling is tedious, and ships are used only for pleasure and such out-of-the-way trips as this. Journeys from place to place over established routes are made in large tubes, in which the cars are propelled by electricity. These tubes run both on land and water, being suspended in the latter a little way below the surface. Both tubes and cars are air-tight, and the adjustment is so perfect that the cars slide along with the greatest ease. ”

“ XXXIV. So, in a little while, there were more than a thousand navigators engaged day and night, and in all parts of the ocean, in making and recording observations according to a uniform plan, and in furthering this attempt to increase our knowledge as to the winds and currents of the sea, and other phenomena that relate to its safe navigation and physical geography. ”

“ The horizon of a man in a small boat is only about 3 miles away, but, if he climbs to the bridge of a steamer some 60 feet above the water, he finds that the horizon has receded until he has a range of about 9 miles.
The fact that the horizon can be altered by changing the altitude should appeal to every navigator as a possible means of getting a horizon in foggy weather, by going aloft or getting as low as possible, provided the fog bank is lying above or close to the water. ”

“ As my airship plowed ahead the wind fluttered my coat violently, as on the deck of an Atlantic liner, tho in all other respects it is more like river navigation with a steam-boat. It is not at all like sail navigation and all talk about “tacking” is meaningless. Imagine the air current to be a river running 10 miles per hour. If you go against the current, making 20 miles per hour, your net progress will be but 10 miles per hour. ”

“ Thus it will be seen that in navigation there are currents in the sea and currents in the air to be considered, and that it requires a great deal of forethought, and knowledge, and experience, to take a ship in safety and with speed round the world. ”

“ This system serves a dual purpose, for the water circulates throughout all the cabins of the section, and if necessary through Nos. 2 and 3 section as well, thus affording a warmth that is appreciated when we are flying at a great altitude. Ten to twelve thousand feet is our favourite height, for then we can command a field of vision—provided the atmosphere is clear—of anything up to one hundred and twenty miles. Now for the upper navigation-room—your future post. ”

“ In practical navigation a vessel commences her voyage and attempts to sail in a certain direction, but the well-known elements of compass error, variation and deviation, current, wind, seas and poor steering all divert the vessel from the projected course. In dead reckoning a navigator strives to keep track of his position by keeping a record of actual courses steered and distances run. ”

“ He will be able to take a meridian observation with fair accuracy, and from that observation, with ten minutes of figuring, work out his latitude and longitude. And, carrying neither freight nor passengers, being under no press to reach his destination, he can jog comfortably along, and if at any time he doubts his own navigation and fears an imminent landfall, he can heave to all night and proceed in the morning. ”

“ The Art And Science Of Navigation Marine navigation blends both science and art. A good navigator constantly thinks strategically, operationally, and tactically. He plans each voyage carefully. As it proceeds, he gathers navigational information from a variety of sources, evaluates this information, and determines his ship’s position. ”

“ The sun and stars are considered to be stationary for all navigational purposes, the apparent movements of these bodies being entirely due to the motions of the earth. The result of our daily rotation from west to east is, that the heavenly bodies march past our meridian m a majestic procession for 24 hours, after which the performance is repeated. ”

“ The difficulty of navigation is due to the fact that unless there is absolutely no wind, the compass, after the corrections for variation and [Pg 35] deviation are made, only shows the direction in which the head of the flying-boat is pointing and not the direction in which it is travelling, and the air-speed indicator only gives the speed of the machine in relation to the air. ”

“ At two points (the equinoxes) on opposite sides of the earth, and at right angles to the direction of its inclination, the equator and terrestrial ecliptic cross each other at the “water’s edge.”
The sun is always exactly overhead for that point of the earth which is nearest to it. This is an essential fact to remember in navigation. Bearing in mind that the sun is stationary and ignoring for a time the rotation of the earth, each advance in its orbit brings about a change of bearing of the sun and a new position becomes the nearest point, and thereby directly beneath the sun. ”

“ In order to facilitate a simple explanation of New Navigation it will be brought to mind that every heavenly body has a corresponding point on the earth directly beneath it, which bears the same relation in latitude and longitude to the earth, that the body does in declination and right ascension to the celestial sphere. To an observer at such a sub-celestial point the body is in the zenith with an altitude of 90° ”