Page:Popular Science Monthly Volume 30.djvu/881

Rh inches square, and containing usually two or three grotesque figures of men and animals. The design of these picture-writings shows considerable variety and freedom of treatment as compared with the large-sized human figures, in the execution of which the artist seems to have been bound by conventional rules. The largest of the stone animals is perhaps the most remarkable of all the monuments; its measurement is roughly a cube of eight feet, it must weigh nearly twenty tons, and it rests on three large slabs of stone. It is shaped like a turtle, and is covered with the most elaborate and curious ornament, and with tables of hieroglyphics and cartouches of picture-writing. The greater part of the ornament throughout these carvings is formed from the grotesque representations of the human face or the faces of animals, the features frequently so greatly exaggerated that it is most difficult to recognize them; but a careful examination enables one almost invariably to trace back to this facial origin what, at first sight, appears to be merely conventional scroll-work. Forms derived from leaves or flowers are altogether absent; occasional use is made of a plaited ribbon, and a very free use of plumes of feathers, which are often most gracefully arranged and beautifully carved. The fifteen monuments are divided into two groups; in one the human figures are all of men; in the other, of women. It might be rash to argue from this that women had attained a high place in the social arrangement of the people who raised these monuments; but there is one other feature that certainly may be admitted as showing an advanced and peaceful condition of existence, and that is the entire absence of any representation of weapons of war." Casts of the largest of the monoliths, of the turtle, and of all the tablets of hieroglyphics, are on exhibition in the Archaeological Museum at Cambridge, England.

Petroleum in Egypt.—Oil has been "struck" in Egypt by boring in the Jebel Zeit (Oil Mountain), on the shore of the Red Sea, one hundred and eighty miles from Suez. Petroleum has long been supposed to exist in the country, for the ancient mummy-cloths were soaked in it, and the exudations from the fissures of this very mountain have been used by the natives, from time immemorial, as a specific for rheumatism and skin-diseases. Oil was definitely mentioned as a production of the Red Sea country, and an analysis of a sample of it was given in a book published by Mr. Norman Tate, in 1864, but nothing more precise is known concerning the statements he makes. Some two years ago, M. Debay, a Belgian engineer, proposed to exploit for petroleum, and finally obtained a concession to do so, which was to expire on the first day of March, 1886. He started his borings after a long delay, and at last, on the last day of the life of his privilege, got at the depth of thirty-five metres signs of oil sufficient to satisfy the conditions of his contract. With continued borings an outflow of five hundred tons of mixed water and petroleum has been obtained, of which the pure petroleum constituent was estimated at at least one hundred and fifty tons. The Egyptian Government is looking out for companies to work its oil. It intends to avoid a monopoly, and will divide the land into portions, which will be ceded for a sum in cash and a royalty on all production.

The Theory of Earthquakes.—Professor J. S. Newberry defines an earthquake, so far as present knowledge permits it to be defined, as a movement caused by a shrinking, from the loss of heat, of the heated interior of the earth, and the crushing together and displacement of the rigid exterior as it accommodates itself to the contracting nucleus. As the nucleus contracts, the solid crust can not accommodate itself, moment by moment, to the loss of volume, for it resists by its rigidity and is brought into a state of strain. This is relieved from time to time, whenever it passes the resistance of the materials composing the crust, by a crushing together and displacement of the surface rocks. These are faulted or folded; that is, are either thrown into great waves by lateral pressure, or the arches are broken and fissures are produced at right angles to the line of thrust. The rocks forming the sides of these fissures slide on each other, forming what geologists