Page:Science vol. 5.djvu/255

 building, and build large masses of stone or brick upon which piers for delicate inatriiments could be placed. The conditions for 8t«adi- ness, however, in the Jefferson physical lab- oratory, ore fulfilled anfflciently for practical purposes-

The laboratorj-, together with its heating and lightiug arrangemeHls and engines, cost a hun- dred and Eileen thousand dollars. This sum was given by Mr. Thomas Jefferaon Coolidge, on conilition that seventy-live thousand dollars more should be raised for maintaining the lab- oratory. Many friends of the university con- tributed to this income fund.

The laboratory is named in honor of Thomas Jefferson, the ancestor of Mr, Coolidge. Jef- ferson, while president of the United States, evinced great interest in the proniotioa of university education in America, — an interest which took a practical form in the foundation of the University of Vit^nia ; and the seed thus sown, it will be seen, bears frnit even unto Ihia ^dw'. John Thowubiock.

^^F*^^ presence of old beaches above present ^^filter-level is readily perceived on many mod- ern lake and ocenn margins, notably around OrealSalt Lake and on the Peruvian and Chilian coasts of South America. The evidence of similar beaches in geological groups cannot be considered so decisive, nor is it so conspic-

That most of the strata of the Cincinnati group were deposited in deep water is proba- ble. They contain manj' fossils whose modern relatives live in deep sens, and it is not likely thai it was different with the ancient forms. Brachiopods, crustaceans, bryozoans. polyps, are all inhabitants of comparatively deep water, at least ; and these forms are found in extraonlinary abundance in the Cincinnati group.

Two apparently well-defineil shore-lines have been noticed in the rocks in the vicinity of Cincinnati. One of these was first referred to hy Dr. Locke some forty years ago. It crops out about three hundred feet above low-water mark, and is characterized by the dumb-bell fossil known as Arthraria, It is apparently to this horizon that Miller refers in the Cincinnati guarterly journal of science, i. 64.
 * he speaks of wave-hues in the rocks.

��"Theae wave-like rocks ore compoaed in a very large part of frogmetila ot crlnolds, principally o( the Heterocrin us simplex, and appear lo have been formed by Qie action of the waves In first brenking to pieces the animal skeletons, and then leaving them In ridges, as if to mark for all future time the course of the waves. These rocks are found In all Ihe hitis about Cincinnati, and aa far east as Plalnvllle [nine mtles], A number of foBsila are found below [tieee rocks that hays' thus far not been found above tbeni ; and, on the other hand, many have been found above that have not been found below. . . . llietoseiU wbichare coramoii to both elevBtions compri«e rauie tban half of all those found below these rochs. And yet, on further exam mat ion, It may appear that the causes which led 10 the formation of these waves in llie rocks, also caused a considerable cbaoge in the uoi- mals which inhabited the ocean at that time."

Here the probable existence of n shorc-liuc is indicated. It seems to mark one of those periods of elevation which occurred during the deposition of the strata. The fact that many fossils are found above which are not common below, would indicate a serious disturbance of conditions, — ^a change which caused the ex- tinction of many previously common species, and allowed the introduction of a few entirely new ones.

It is at about this horizon that rocks bear- ing marks of surface water- washings, and evi- dent traces of the action of trickling water, are found. There are also indications in the rocks of the rippling of water, such as could occur only along the margin of a shallow sea. These marks have been described as Algae under various names, but their true character has been shown by comparing them with modern marks of a known origin.

A second ancient shore-line, as it api>car9 to be, crops out at various points in the vicin- ity of Cincinnati. Probably the best exposure is at Ludlow, Ky., along the Ohio River, op- posite the city. Professor Orton, in speaking of the waved structure of the rocks, refers to this localitj- as follows : ' —

" The rocks exhibiting this structure at the iioliil named ] river-quarries] are the most compact beds of Uie foasillferous limestone. The bottom of llie waved layer i» generally even, and beneath it la al-

��ways found an even bed of shale The upper sur- face Is divcrslfled, as Its name suggests, with ridges and furrows. The interval between the ridi;es vai'ies; Init In many instances it is about four feet. The greatest tbicknesa of the rtdge is six or seven inches, while the stone is reduced to one or two inches at the bottom of the furrow, and somelimes it entirely dis- appears " (see figure).

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