Apkil-10, 1886. 



SCIENCE. 



287 



the hard and fast line of 85° north latitude, where 

 the ice-cap is supposed to be fixed by centrifugal and 

 other forces, and insists on my saying I will have 

 a smooth ice-cap to travel over to the pole ; whereas, 

 in both cases, about 85° north and a comparatively 

 smooth ice-cap are intended. 



"And in returning, he intends to use the southern 

 drift of the ice," etc. I speak of, and lean upon, 

 probabilities in my theory altogether; and the mil- 

 lions of square miles of ice that drift out of the 

 Arctic Ocean do not come from near the pole. 

 Capts. Nares and Markham, nor any one else, has 

 ever seen a ' paleocrystic sea of ice.' All the ice 

 ever witnessed by the eye of man has been ' broken 

 floe' or drifting 'pack' of but one or two years' 

 growth, or at most of but a few years' growth, that 

 breaks up and drifts away from the outer edge of the 

 ice-cap under discussion. 



"While drifting in the Jeannette, we observed a 

 large 'old-time' floe piece (about sixteen miles area) 

 that might have been of any age. It certainly was 

 very much older than any surrounding ice ; and it had 

 the appearance of what might be termed a piece of the 

 paleocrystic ice-cap near the pole, that had been 

 broken off farther up into the upper ' fringes ' of the 

 cap, and had drifted away. 



This floe piece has no reference to bergs that are 

 made upon the land, and take ages to form, but to 

 the ice of the salt sea. Hard as dolomite, and of the 

 dead color of marble, it was entirely different from 

 the pack and floe ice of 70° or 80° north latitude. 

 This is one more reason why I believe, that, as we 

 proceed toward the pole north of 85°, we should find 

 the disputed ice-cap formed of this older ice. 



Dr. Boas says, that, " if it can be proved that an 

 ice-cap cannot exist, his [my] plan must needs fall to 

 pieces. . . . No doubt the centrifugal pull at a cer- 

 tain parallel will be equal on every meridian," etc. 



But the very mile of ice that Dr. Boas depends 

 upon to pull the ice-cap from its place, and hurl it 

 down toward the equator, is just the mile or miles of 

 ice that break away from the ice-cap because of the 

 weakness of the ice at the fringes ; and, as it breaks 

 away, the cap regains its equilibrium. Whether the 

 strength of the ice at the pole will withstand the 

 centrifugal force, tending to carry it toward the equa- 

 tor, will depend upon the velocity of that force, and 

 the amount of hold and the number of holds the 

 islands have upon the cap, as well as the contending 

 currents and other forces that are continually at war 

 with each other. And I do not concede that my 

 argument referring to an equal pull (comparative and 

 then equalized again) by the centrifugal force cannot 

 be maintained. 



Even though all my theories fall to the ground, I 

 am doing just what Dr. Boas wants his readers to 

 believe I am not doing; that is, I am not depending 

 upon my theories alone for my scheme of advance to- 

 ward the pole, but I am depending upon the lessons 

 taught by 'former experiences,' and 'not on vague 

 theories.' 



I propose to go by way of Franz Josef Land, for the 

 reasons that it is the northernmost land known on 

 the face of the earth; it is readily accessible every 

 year; retreat from this land is sure and safe. By 

 this route alone are we enabled to hold to the land 

 to the farthest point north, and I would not leave the 

 land at all if it extends all the way to the pole. 



But if it does not extend all the way to the pole, 

 then I must take to the ice, over which I believe 

 I will have easy travelling, compared to that south 

 of 80°, where the motion is greater than toward 

 the pole, and where most of the observations of 



the ice conditions have been made. All, all else is 

 theory. 



I have no desire to go to the Arctic to perish. It is 

 my knowledge, founded on personal experience and 

 that of others that I have studied intently, that makes 

 me believe that I can go to the pole via Franz Josef 

 Land with a greater degree of safety than by any 

 other route, and that it is the route of the future. 



I thank Dr. Boas for his courtesy and words of 

 praise. I do not class him with the narrow-minded 

 obstructionists of whom he speaks; but I cannot 

 agree with his hair-splitting arguments, or his hard 

 and fast lines of demarcation, in which he insists 

 that my theories are based on erroneous data, or in 

 opposition to the standard authorities of the day. 

 Geokge W. Melville, 

 Chief engineer U. S. navy. 



Columnar structure in sub-aqueous clay. 



During the summer of 1883, in the vicinity of 

 Menomonee, Dunn county, Wis., I was fortunate 

 enough to see, while it was still fresh, a deep railway 

 cut through the sub-aqueous clays which overspread 

 that region, reaching up to considerable altitudes 

 above the Red Cedar River. The cut was something 

 less than a hundred feet above the stream, and be- 

 tween twenty-five feet and thirty feet deep. Be- 

 neath the shallow soil was a stratum of distinctly 

 laminated brown-yellow clay-loam about ten feet in 

 thickness. Beneath this was a stratum of clay of a 

 peculiar greenish hue, also distinctly laminated, 

 and through which occasional sandy partings were 

 traceable. This stratum was about five feet in 

 thickness, and was followed, in descending order, by 

 stratified sand, which extended to the bottom of the 

 cut. 



In the second clay stratum, reckoning from the 

 top, columnar structure was beautifully developed. 

 Not only was this structure conspicuous as seen in 

 the nearly vertical face of the cut, but several of the 

 hexagonal columns had individually separated from 

 the others, and, after falling a number of feet from 

 their natural position, still preserved their integrity 

 as they lay at the bottom of the cut. The columns 

 varied in diameter from ten to fifteen or sixteen 

 inches. They were uniformly, but not regularly, six- 

 sided, and could be divided easily across their longer 

 axes, parallel to the bedding planes, so that each 

 column was separable into regular sections. When- 

 ever this parting was made (and the experiment was 

 repeated several times), the opposing surfaces, after 

 separation, were never plane, but always showed a 

 greater or less curvature, convexity fitting concavity. 

 If my memory serves me rightly, the convexity was 

 at the lower end of each section, though, unfortu- 

 nately, I find nothing in my notes on this point. 



Another interesting feature was observable on the 

 cross-section surfaces ; viz., a distinctly concentric 

 structure. This, in some cases, was very conspicu- 

 ous; in others, to be discovered only on close inspec- 

 tion. In more than one case, the concentric lines, 

 which were real structure-lines, and not merely lines 

 of coloration, were almost continuous around the 

 column, but they were more commonly somewhat 

 interrupted. The concentric lines were generally 

 very numerous, and therefore closely approximate, 

 and more commonly best developed just about the 

 centre, or else near the exterior of the column. 



This structure would seem to be an additional con- 

 firmation of the hypothesis which ascribes columnar 

 structure to concretionary action. 



Beloit, Wis., March 25. R. D. SALISBURY. 



