Waterbury evening Democrat., 1892-05-17
TREASURES FROM HE Rpcks.
Remarknt1c Curiosafaea af the Gaolomaoma
 Snrvey--EKow Akonntnlnn Ars Made.

Remarkal1ze curiosataee af the Geological
 snrvsy-How AEonntnlna Are Made.
 Two very remarkable curiosities are placed side by side on a littleshelfat at the geological survey. One is lump of chalcedony as big as a childss fist, white and translucent. It is but thin shell, and when held to the light Is seen to be nearly filled with water, which flows about as the object is turned this way and that. What makes it interesting is that the water has undoubtedly been inclosed and hermeticaIly sealed in this natural receptacle for thousands and thousands of years. Probably it was there long before Moses was born, and yet not g drop of it has evaborated. Originally there was a cavity in the rock, formed by volcanic bub- ble. Water percolated into 1t, bringing in solution silex, which was deposited on the walls of the little hollow in coating of chalcedony. At length it would have been filled up solid with beautiful crystals, forming one of those 'tgeodes," as they are called, which are natures treasure caslzets, found con cealed in rocky formations where least expected, and revealing wonders of brilliant color. Agates are made in the same fashion. However, in this in stance the small channel by which the water flowed in and out became closed up in some way and so the process stopped. After the lapse of no one can tell how many centuries the stony mass containing the chalcedony chamber with its liquid contents was broken open and itfel out, being loose.
 The other curious object above re ferred to is what appears to be petri fled oyster, cut through so that one sees it apparently on the half-shel1, just as it would look when opened fresh for a customer. It was found in chalk-beds formed largely of the shells of various bivalves, probably many oysters and clans among them. The so-called heart" of the animal, which is it's big muscle, and all the other parts are wonderfully distinct. There is even 8 small pearl in it seemingly. Yet it is not an oyster at all, but merely one o1 those marvellous limitations which na, ture makes of her own works in freak. ish moods.
 The government rock sharps find many surprising curiosity among the rocks which it is their business to inves- tigate. Just now at the office of the geological survey they are engaged in building imitation mountains for the purpose of studying the way in which the eternal hills were formed by the crumpling due to the contraction of the earth's crust. The coal basins and other valuable mineral deposits in many parts of the United States have undergone just such crumpling, so that it will be profitable to ascertain the laws govern ing it.
 These imitation mountains are built of wax, hardened or softened by mixing it with other substances, so that it shall resemble in consistency the brittle rocks near the surface of the earth or the plastic rocks which are in that condi- tion because of the great pressure that exists even at depths of only two or three miles. as the case may be. The mixture is cast in layers of a given thickness by melting and flowing it in W ooden trough. When each layer has hardened it is taken out and a num- Der of the layers thus made are super imposed one upon the other, like layers of jelly cake, representing geological strata. The next process is to place the layers in 8 machine, piling shot on top of them to represent the force of gravity, after which pressure is applied from the ends very slowly by piston advanced with a screw. This causes them to crumple up, and under the artificial contraction they are found to take precisely the forms of mountain ranges like the Alleghenies.- Washing ton Star,