The North Pole - Robert E. Peary (e book reader pdf .txt) 📗
- Author: Robert E. Peary
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Unexplored inlet, 154. Union, Cape, 110, 118, 188, 332. United States, 170, 316.
Victoria Head, 95. Victory, s.s., xviii. "Voyage of the Discovery," 180. "Voyage to the Polar Sea," 180.
Wakiva, s.s., 34. Walrus, xvi, 65, 77, 79, 80-87, 169, 333. Walrus-hunting, 80-87. Wardwell, George A., 20, 23, 101, 326. Weekly bill of fare, 164. Weesockasee, 158. Wesharkoopsi, 84, 85, 142, 145, 168, 235. Weyprecht, xxvi, 180. Whale-boat, 29, 31, 79, 80, 84, 95, 123. Whale factories, 34. Whale Sound, 3, 54, 74, 79, 87, 328. Whales, xvi. White Nile, viii. Whitney, Harry, 75, 333. Willoughby, 321. Windward, s.s., 93, 130. Winter solstice, 184. Wiseman, John, 23, 326. Wolf, 54. Wolf, Dr., 20. Wolstenholm Sound, 73, 79. "World's Ensign of Liberty and Peace," 296. Wrangell Land, xxiv.
York, Cape, 32, 35, 39-46, 70-73, 271, 334.
[1] The instruments used in taking observations for latitude may be either a sextant and an artificial horizon, or a small theodolite. Both these instruments were taken on the sledge journey; but the theodolite was not used, owing to the low altitude of the sun. Had the expedition been delayed on the return until May or June, the theodolite would then have been of value in determining position and variation of the compass.
The method of taking meridian observations with a sextant and an artificial horizon on a polar sledge journey is as follows: if there is any wind, a semi-circular wind-guard of snow blocks, two tiers high, is put up, opening to the south. If there is no wind, this is not necessary.
The instrument box is firmly bedded in the snow, which is packed down to a firm bearing and snow is packed around the box. Then something, usually a skin, is thrown over the snow, partly to prevent any possible warmth from the sun melting the snow and shifting the bearing of the box; partly to protect the eyes of the observer from the intense reflected glare of light from the snow.
The mercury trough of the artificial horizon is placed on top of the level box, and the mercury, which has been thoroughly warmed in the igloo, is poured into the trough until it is full. In the case of the special wooden trough devised and used on the last expedition, it was possible to bring the surface of the mercury level with the edges of the trough, thus enabling us to read angles very close to the horizon.
The mercury trough is covered with what is called the roof—a metal framework carrying two pieces of very accurately ground glass, set inclined, like the opposite sides of the roof of a house. The object of this roof is to prevent any slightest breath of wind disturbing the surface of the mercury and so distorting the sun's image in it, and also to keep out any fine snow or frost crystals that may be in the atmosphere. In placing the trough and the roof on the top of the instrument box, the trough is placed so that its longer diameter will be directed toward the sun.
A skin is then thrown down on the snow close to the box and north of it, and the observer lies down flat on his stomach on this, with his head to the south, and head and sextant close to the artificial horizon. He rests both elbows on the snow, holding the sextant firmly in both hands, and moving his head and the instrument until the image or part of the image of the sun is seen reflected on the surface of the mercury.
The principle on which the latitude of the observer is obtained from the altitude of the sun at noon is very simple. It is this: that the latitude of the observer is equal to the distance of the center of the sun from the zenith, plus the declination of the sun for that day and hour.
The declination of the sun for any place at any hour may be obtained from tables prepared for that purpose, which give the declination for noon of every day on the Greenwich meridian, and the hourly change in the declination.
Such tables for the months of February, March, April, May, June, and July, together with the ordinary tables for refraction to minus 10° Fahrenheit, I had with me on pages torn from the "Nautical Almanac and Navigator."
[2] Ignorance and misconception of all polar matters seem so widespread and comprehensive that it appears advisable to introduce here a few a b c paragraphs. Anyone interested can supplement these by reading the introductory parts of any good elementary school geography or astronomy.
The North Pole (that is, the geographical pole as distinguished from the magnetic pole, and this appears to be the first and most general stumbling block of the ignorant) is simply the point where that imaginary line known as the earth's axis—that is, the line on which the earth revolves in its daily motion—intersects the earth's surface.
Some of the recent sober discussions as to the size of the North Pole, whether it was as big as a quarter, or a hat, or a township, have been intensely ludicrous.
Precisely speaking, the North Pole is simply a mathematical point, and therefore, in accordance with the mathematical definition of a point, it has neither length, breadth, nor thickness.
If the question is asked, how closely can the Pole be determined (this is the point which has muddled some of the ignorant wiseacres), the answer will be: That depends upon the character of the instruments used, the ability of the observer using them, and the number of observations taken.
If there were land at the Pole, and powerful instruments of great precision, such as are used in the world's great observatories, were mounted there on suitable foundations and used by practised observers for repeated observations extending over years, then it would be possible to determine the position of the Pole with great precision. With ordinary field instruments, transit, theodolite, or sextant, an extended series of observations by an expert observer should permit the determination of the Pole within entirely satisfactory limits, but not with the same precision as by the first method.
A single observation at sea with sextant and the natural horizon, as usually taken by the master of a ship, is assumed under ordinary satisfactory conditions to give the observer's position within about a mile.
In regard to the difficulties of taking observations in the arctic regions, I have found a tendency on the part of experts who, however, have not had practical experience in the arctic regions themselves, to overestimate and exaggerate the difficulties and drawbacks of making these observations due to the cold.
My personal experience has been that, to an experienced observer, dressed in furs and taking observations in calm weather, in temperatures not exceeding say 40° below zero Fahrenheit, the difficulties of the work resulting from cold alone are not serious. The amount and character of errors due to the effect of cold upon the instrument might perhaps be a subject for discussion, and for distinct differences of opinion.
My personal experience has been that my most serious trouble was with the eyes.
To eyes which have been subjected to brilliant and unremitting daylight for days and weeks, and to the strain of continually setting a course with the compass, and traveling towards a fixed point in such light, the taking of a series of observations is usually a nightmare; and the strain of focusing, of getting precise contact of the sun's images, and of reading the vernier, all in the blinding light of which only those who have taken observations in bright sunlight on an unbroken snow expanse in the arctic regions can form any conception, usually leaves the eyes bloodshot and smarting for hours afterwards.
The continued series of observations in the vicinity of the Pole, noted above, left me with eyes that were, for two or three days, useless for anything requiring careful vision, and had it been necessary for me to set a course during the first two or three days of our return I should have found it extremely trying.
Snow goggles, as worn by us continually during the march, while helping, do not entirely relieve the eyes from strain, and during a series of observations the eyes become extremely tired and at times uncertain.
Various authorities will give different estimates of the probable error in observations taken at the Pole. I am personally inclined to think that an allowance of five miles is an equitable one.
No one, except those entirely ignorant of such matters, has imagined for a moment that I was able to determine with my instruments the precise position of the Pole, but after having determined its position approximately, then setting an arbitrary allowance of about ten miles for possible errors of the instruments and myself as observer, and then crossing and recrossing that ten mile area in various directions, no one except the most ignorant will have any doubt but what, at some time, I had passed close to the precise point, and had, perhaps, actually passed over it.
[3] Drowned April 10th, returning from 86° 38´ N. Lat.
[4] Transmitted by O. H. Tittmann, Superintendent, Coast and Geodetic Survey.
[5] These observations were made by Marvin and MacMillan, assisted by Borup, seaman Barnes, and fireman Wiseman.—R.E.P.
[6] Results from Greely's observations, 1881-83, covering a period of nearly two years.
[7] Observations made in 1875-76 and 1881-83. Greely's Report, Vol. II, p. 230.
[8] Greely's Report, Vol. II, pp. 196, 197, 220, 221. Hourly readings used.
[9] Observations made in 1881-83.
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