Page:Science vol. 5.djvu/311

 ihe hard aud fsst line o( M" north latitude, where Ihe ice-cap is supposed to be Hxiid by cetitrlfugftl and other forces, and insists on my wyiiig I will have a smooth ice-cap to travel over to the pole; whereas, ID both cases, about 85° north and a eniiipaTatieel'/ smooth ice~cap are intended.

"And in returoing, he Intends to u*e the southern drift of the ice," etc. I speak of, and lean upon. probabWlieK iu my theory altugeiiier; and the mil- lions of square miles of Ice that drift out of llie Arctic Ocean do not come from near the pole. Capu. Nares and Marlibam, nor any one else, has erer seen a ' paleocryBtic sea of ice.' All the ice ever witnessed by ilie eye of man lias been ■ brol;en floe' or drifting 'pacit' of but one or two years' crowth, or at most of hut a few year*' growth, that breaiis up and drifts away from the enter edge of the ic«-cap under discussion.

While drifting in the Jeaiinette, we oijserveil a lar^ 'old-lime' floe piece (al>out sixteen miles ar^a) thai niijjiht have beeu of any age. It certainly was very much older than any surrounding ice ; and It had Ibe appearance of what might he termed a /Heceot the paleocrystic ice-cap near the pole, that had been broken off farther up into the upper ' fringes ' of the Mp. and had drifted away.

Thin floe piece has no reference to bergi< that are Dade upon the land, and take ages to furin, but to the ice of the salt sen. Hard as doloinile, and of Ihe dead color of marble, it was entirely cllfierent from Ihe pack and floe ice of T0° or rM)° north latitude. This is one more reason why I believe, that. ».? we proceed toward the pole north of 85°. we should find the disputed iee-cap formed of this older ice.

Dr. Hoas says. that. " If it can be proved that an ice-cap cannot exist, hrs [my] plan must needs fall to pieces. . . . Xo doubt the eentrltugal pull at a cer- tain p»nUleI will be equal on every meridian," etc.

But the very mile of iee that Dr. Boas depends upon to pull the ice-cap from Its place, aud hurl it (lown toward the equator, is just the mile or miles of Um tJtat break away from the ice-cap because of the weakness of the ice at the fringes; and. as it breaks Kwvjr, thecap regains its ei|uilibrium. Whether the nrength of the ice at the pole will withstand the eentrifngal force, lending 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 Tiot concede that my argnment referring to an equal pull (comparative and then equalized agsjn] by the centrifugal force cannot be maintained.

EveD 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 apon my theories alone for my scheme of advance to- ward the pole, but I am depending upon the lessons tanght by 'former experiences,' and ' not on vague theories.'

[ propose to go by way of Fran^i Josef Land, for the reasons tlinl it is IJie northernmost land known on the face of the earth; It Is readily accessible every yean retreat from this land is sure and safe. By ihis route alone are we enabled to hold to the land lo 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 t believe I will have easy travelling, compare<l to that soutlt of 80°. where the motion is greater than toward Ihe pole, and where most of the observatli

��the ice conditions have been made. .Ml. all else is

I have no desire to go to the Arellc lo perish. It is my knowledge, founded on personal experience and that of others that 1 have studied intently, that makes tne hetleve that 1 can go lo the pole tiia Franz Josef Land with a greater degree of safety than by any other route, and that, il is t/ie route of the future.

1 tliank Dr. Boas for his courlesy 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 tliat my theories are based on erroneous data, or in opposition lo the standard aulliurilies of the day. Gkokok W. Mki-ville, Clii^ en'jlneer U. S. imsy.

Columnar atructure iu aub-aqueons clay.

During the summer of ISK3. in the vicinity of Menomonee, Dunn county. Wis., I was fortunate enough lo see. while it was still fresh, a deep railway cut through the sub-aiiueous clays which overspread that region, reochlnic up to consldeinble attitudes above the Red Cedar River. The cut was lomethtng 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 hrown-yellow clay-loam about ten (eet in thickness. Beneath this was a stratum of clay of a peculiar greenish hue, also distinctly lamitial«d. and through which occasional sandy partlnf!s were traceable. This stratum was about Ave feet in thickness, and was followed, in descending order, by stratified sand, which extended to the bottom of the

In the second clay stratum, reckoning froni the top, columnar structure was beautifully developed. Not only was this structure conspicuous as seen in the nearly vertical face ot the cut, but several of the hexagonal columns had iudlvldually separated from the others, and, after falling a number of feet from their natural position, still preserved their inte^ity 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 beddiug planes, ao that each column was separable into regular sections. When- ever this parting was made (atid the experiment was repeated several timesi, the opposing surfaces, after separation, were never plane, but ^wajs allowed a

freater or less curvature, convexity fitting concavity. f my memory serves me rightly, the convexity was at the lower end of each section, though, unfortu- nately, I And nothing in my notes on this point.

Another interesting feature was observable on the cross-section surfaces; viz., a distinctly concentric structure. Tbis, in some cases, was very conspicu- ous; In others, to be discovered only on close iuspec- tion. In more than one case, the concentric lines, which were real atructure- lines, and not merely lines □f coloration, were almost continuous around the column, hut they were more commonly somewhat interrupted. The concentric lines were generally very numerous, and therefore closely approximate, an<l moro commonly best developeil just about the centre, or else uear the exterior of the column.

This structure would seem to he an additional con- firmation of the hypothesis which ascribes columnar structure to concretionary action.

tieluil, Wll.. MurchSA. R. D. SALISBVKV.

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