Page:Popular Science Monthly Volume 33.djvu/231

Rh innumerable caves. So far as caves are concerned, the formation in Kentucky surpasses it, but its veins of lead and fluor-spar—blue John as it is called—are peculiar to it.

Farther south, near Bedford, the oölites and Oxford clay are well exposed, beds not much developed in our Eastern States, and not far off, near Cambridge, the chalk comes in. The Cambridge greensand, formerly worked for phosphates, is nearly worked out, I believe, but hosts of the charming little ammonites, brachiopods, and crabs that the workings yielded, are stored in the museum, awaiting exchange. In the museum, too, you may learn where the chalk is best to be seen, and whether any recent excursion has probably cleaned the workmen out of all their good sea-urchins. They say that from Cambridge to the Ural Mountains no land rises above two hundred feet, and certainly off toward the fen-land which man has redeemed from the sea it looks plausible. What a change in the geography and politics of Europe a submergence of two hundred feet would cause!

Back once more in London, other excursions invite us (see 2, and the reports of excursions of the various Geological Societies and meetings of the British Association) to the Isle of Wight, or to the Lizard, which is, naturally enough, serpentine. But between so many it is easier to skip them all than make a choice. Let us follow the track of the Geologists' Association to Belgium (14). Reaching Brussels, we find in the Musée Royale near the picture-gallery a magnificent collection, unique in its iguanodons, and finely arranged to illustrate geological excursions. Notice, for example, the section along the Meuse, with illustrative specimens.

In the suburbs of Brussels the work of the builder is continallycontinually [sic] opening and closing sections in the tertiary sands, but somewhere surely one can see the grès fistuleux of the Bruxellien, whose curious columns of sandstone, consolidated around annelid tubes, stand up amid the yet unconsolidated sand. Various nummulite zones occur, but not recent information as to where to pick up these coins of Nature's realm is valueless (compare, however, 14). Shark's and skate's teeth also occur, and occasional crabs. Very close to Calevoet Station I picked up a chunk of half-consolidated sand fairly bristling with teeth. The pamphlet (14) covers the ground so well that I need not dwell on Belgian geology, except to call attention to the agricultural geological soil map (15). Nor does Holland call for particular remark, except that one should not fail to run down to Katwykam-Zee from Leyden, or Scheveningen from the Hague to see the mighty dune-bulwarks that protect the land from the storms of the North Sea.