"The most complete proof that the earth is a globe consists in the fact that travellers over its surface, whether by sea or land, always find the distance between different stations, exactly such as agree with the calculated distances." 1
The above sentence is such a compound of childish fable, and either unwarrantable assurance or ignorance,, that, were it not that the author is an ardent and extensive, but not a careful or over-scrupulous writer, in defence of the Newtonian astronomy, it would really be unworthy of criticism. It is one of those utterances which indicate a desperate determination to support a cause at all hazards, and without regard to any evidence but such as agrees with a foregone conclusion. So great is the number of those who advocate the earth's rotundity, who do not hesitate to show the same spirit, that it is really a difficult thing to feel that respect for them which persons who merely differ in opinion ought at all times to show and feel towards each other. What can be more misleading, or illogical, or even more the reverse of fact, than to say that "travellers always find the distance between different stations exactly such as agree with the calculated distances, and therefore the earth is a globe?" A mariner at sea, coming in contact with new land, immediately ascertains the latitude by taking the sun's altitude at noon, and the longitude by the local meridian time in relation to the meridian time at Greenwich. Neither the altitude of the sun, nor the time by chronometer, has
any logical connection with the shape of the earth. It is true, elements connected with the supposition of the earth's rotundity may be mixed up with the mode of finding latitude and fixing longitude; and anyone may afterwards readily find the places again, by sailing until the sun's altitude and the time by chronometer are the same as those first published, when, of course, they must have arrived at the same position, whether the earth is a globe or a plane. It is altogether wrong to say that places, either on land or sea, are found by calculation, except that when places have already been found, and their latitudes and longitudes given, calculation--which is merely the use of formulæ resulting from previous observation--may be used to find them again. But, primarily and essentially, places are found by observation, and not by calculation. If anyone will read the reports of the leading circumnavigators, and travellers of different countries, they will find many instances where calculation has failed to agree with observations, and where renewed observations have had to be made before anything like the proper position of places in the maps could be fixed. In the majority of instances, where calculation, even when mixed up with some amount of observation, has been relied on, errors have been found.
"Assistant surveyor F. Gregory, and Mr. S. Trigg, in a short exploration trip to the eastward of the Geraldine Mine, had succeeded in discovering a large tract of good country, well grassed. . . . Mr. Gregory, in hip report, notes a 'difference of 17 miles in latitude, and something more in longitude, throughout the eastern portion.'
between himself and Mr. Austin--a difference for which he cannot account. 1
"This promontory (North Cape, Prince Edward's Island) we found by good observation to be in latitude 46 ° 53´ S., and longitude 37° 33´ E., agreeing very nearly with Cook in the latitude, but differing considerably in the longitude." 2
"By noon (March 9, 1840) we were in latitude 64° 20´ S., and longitude 164 ° 20´ E., and therefore about 70 miles north of the land laid down by Lieutenant Wilkes, and not far from the spot from which he must have supposed he saw it; but having now searched for it at a distance varying from 50 to 70 miles from it, to the north, south, east, and west, as well as having sailed directly over its assigned position, we were compelled to infer that it has no real existence." 3
Either Lieutenant Wilkes or Captain Ross had made a great mistake; or, perhaps the land had disappeared?
In a "Memorandum by Admiral Krusenstern," of the Russian Navy, appended to Lieutenant Wilkes' narrative, several discrepancies respecting true positions are given, and advises that, in addition to the ordinary modes, "absolutely astronomical observations" should be taken. He concludes by saying: "With respect to the coast of South America, Talcahuana, the longitude of which was determined by Captain Beechy to be in 72° 56´ 59″ W., seems to me a well-determined point. Captain Duperrey is not of that opinion; and it remains to be settled whether the longitude of Talcahuana, or Valparaiso, in 71° 33´ 34″ W., deserves the preference." Here is one of
many instances where, in a well-frequented place, a difference exists among nautical calculators, as to its exact position, of 1° 23´ 25″, or (supposing the earth a globe) fully 70 statute miles.
276:1 "Lessons in Elementary Astronomy;" R. A. Proctor, B.A., F.R.A.S., 1871.
278:1 "Australian and New Zealand Gazette" for 1857.
278:2 "South Sea Voyages," by Captain Ross; vol. i., p. 47.
278:3 Ibid., p. 285.