Page:Science vol. 5.djvu/271

 Chapel Hill, completed its first year of existence last autumn. In its first report it is stated to have seven life-members, seventy-five regular members, and seventy-four associates. Monthly meetings have been held in which the interest taken was encouraging. The papers published in the first numbers of the yearly report of the society are of good character, and receive much of their inspiration from the chemical laboratory of the University of North Carolina. A biographical sketch and portrait of Mitchell are prefixed.

LETTERS TO THE EDITOR. Mr. Melville’s plan of reaching the north pole.

the issue of the New-York Evening post, Feb. 6, I opposed Mr. Melville’s plan of reaching the north pole, as I could not consider the theory on which it is founded is correct. In answer to my remarks, Mr. Melville in the same paper, Feb. 17, maintains his position, and denounces his critics for hindering his endeavors, instead of “sending him to prove his theories he has so much faith in, and permitting him to bring back the necessary facts that alone can carry conviction to the unbeliever without a theory.” He says, “It would be more in the spirit of progress and the advancement of science, if my critics would propound new theories or other plans of progress, rather than simply find fault of say ‘I don’t believe.’” We cannot coincide with this opinion of Mr. Melville, and claim the full right to criticise a plan of exploration before it is set in motion. What is the cause of so many failures of arctic expeditions and other undertakings? Is it the careless neglect of thorough deliberation before entering into expeditions, or is it the hostility of nature? Have we nothing to learn by the Jeannette and the Proteus? If we should claim at any time the right of criticism, we do it now, when the blunders and misfortunes which effected the failures of the last expeditions are deeply impressed on public minds, and nearly extinguish the little interest which is left for scientific work in the Arctic. We consider it in the spirit of progress of science, to prove the fallacy of a plan founded on theories like those of Mr. Melville, which cannot be accepted by scientific men, and must lead to disaster, or will at least be unsuccessful.

It is somewhat difficult to understand Mr. Melville’s theory; and I do not know that I am able to give an explanation of it which will satisfy the author. Mr. Melville supposes that the Arctic Ocean, north of 85° north latitude, is covered by a solid ice-cap kept in a state of equilibrium by the centrifugal force. He intends to start from the northern limit of Franz Josef Land on sledges, travelling over the smooth ice-cap towards the north pole,—a supposed distance of five degrees; i.e., three hundred miles out and three hundred miles back. In returning he intends to use the southern drift of the ice, which will carry him either back to Franz Josef Land or to Spitzbergen, where he would have depots erected for the use of the retiring party.

His view about the ice-cap will be seen from the following quotations (l. c., p. 475): “After crossing the eighty-fifth degree of latitude, the traveller will come to that immovable ice-cap which will in all probability prove to be a palaeocrystic sea of ice and snow. We should have a clear, unbroken surface to travel upon, subject, of course, to fissures and shrinkage cracks.” P. 476, he says, “The countless million square miles of ice annually expelled from the Arctic OCean alone prove the fallacy of a ‘palaeocrystic sea of ice;’” p. 478, “Let the state of the ice be as it may, it certainly can be no worse than the broken path over which the Jeannette’s crew marched.”

From these quotations, it would appear that Mr. Melville is not very certain of the existence of the ice-cap. The assertion, however (p. 479), that “the feat of marching to the pole and back will be easily practicable,” and the fact that his plan is founded on this theory, prove Mr. Melville’s confidence in it. If it can be proved that Mr. Melville’s reasons for the existence of an ice-cap cannot be maintained, if it can be proved that an ice-cap cannot exist, his plan must needs fall to pieces. Let us enter into this proofs singly.

First: “As the centrifugal influence is acting equally in all directions, tending to pull the ice-cap towards the equator, it can only carry away those detailed portions of ice broken near the outskirts of the ice-cap” (p. 474). No doubt, the centrifugal pull at a certain parallel will be equal on every meridian; but, supposing this continuous ice-cap to exist, an equal pull could only come to pass if it extended to the same parallel all around the pole. Every mile added to one side would increase the pull there, and disturb the equilibrium which Mr. Melville requires for his theory. Besides, we cannot imagine any kind of ice strong enough to stand the immense tension effected by the centrifgual force on a solid body of three hundred miles in radius. An approximate computation of the effects of the centrifugal force on a body of ice of three metres’ thickness, extending from latitude 85° to 86°, gives a tension of nearly thirty kilograms on one square centimetre.

As soon as Mr. Melville will grant us the slightest motion of his ice-cap in any direction, he has to give up his theory, as the “nucleus of pointed island peaks, which, if nothing more, will hold the ice fast at the pole” (p. 474), will not any longer hold the cap, but break it up into an immense pack. I suppose Mr. Melville will concede that his arguments referring to an equal pull by the centrifugal force cannot be maintained.

The hydrographical and meteorological theories which he brings forth in favor of his plan cannot be supported from the present state of our knowledge in these sciences.

He supposes that there are two currents,—an equatorial, setting north; a polar, setting south,—and between both a neutral zone which he supposes at about 85° north latitude, where scarcely any current exists. Considering the observations on currents in the polar seas, we cannot unerstand how Mr. Melville can propound such a theory. This is not the place to treat of modern oceanography; and I can only refer to Thomson’s and Carpenter’s works, and to Zöppritz’s mathematical theory of currents, which give a basis to this science not allowing us to form theories like Mr. Melville’s. We may only be permitted to say a few words about the improbability of symmetrical currents such as Mr. Melville supposes. The Arctic Ocean forms a large Mediterranean Sea, with one wide outlet between Greenland and Norway. The exchange of water between the Arctic and the