PETROLEUSE 211 PFENNIG in the United States was 375,000,000 barrels. The development of the internal com- bustion engine, driven by gasoline, has resulted in the growth of a great indus- try in the production of gasoline, which is a by-product of petroleum. The in- creased use of petroleum as fuel oil has greatly increased the consumption. The fuel oil consumption of railroads alone amount to about 40 million barrels yearly. The gasoline production in 1919 was about 3,500,000,000 gallons. Mexico is one of the great petroleum countries. In 1919 the production was nearly 100 million barrels. The produc- tion in Russia decreased greatly on ac- count of the conditions resulting from the war. The possibility of the exhaustion of petroleum fields in the United States has received considerable attention and steps are being taken to conserve the supply as far as possible, or to provide for the control of other fields from which addi- tional supplies can be obtained. The world production of petroleum in 1917 was 506,702,902 barrels, of which about 335,000,000 barrels were produced in the United States. PETROLEUSE, a name given to the women of the French Commune in 1871, accused of helping to burn the Tuileries, city hall, and other public buildings by pouring petroleum on them. The charge has been denied by some historians. PETROLOGY, the study of the miner- alogical and chemical composition of rocks ; including the various changes they have undergone through physical and chemical agencies, either combined or separate. Macroscopic and microscopic examination, together with chemical an- alysis, are the methods pursued. PETROPAVLOVSK, a town of Asiatic Russia, in the province of Akmolinsk, on the river Ishim, 175 miles W. N. W. of Omsk. It is an important military sta- tion, with a fort founded in 1752, and has a large transit trade. Pop. (1913) 42,340. PETROPAVLOVSKI, a fortified town on the E. coast of Kamchatka, was at- tacked by an English and French squad- ron, Aug. 30, 1854. They destroyed the batteries, but failed in taking some Rus- sian frigates, except the "Sitka," a store ship and the "Pique." Admiral Price was killed. A party of 700 sailors and marines landed to assault the place, but fell into an ambuscade ; many were killed, including Captain Parker and M. Bou- rasset, English and French officers. The objects of the attack were not attained. After this the Russians greatly strength- ened their defenses, but on May 30, 1855, the allied squadron in the Pacific arriv- ing here found the place deserted. The fortifications were destroyed, but the town was spared. The Russian ships escaped. PETROZAVODSK, a town of Russia, on the W. shore of Lake Onega, 300 miles N. E. of St. Petersburg, has a cannon foundry and small-arms factory, built in 1774. PETUNIA, a genus of American her- baceous plants, natural order Solanacex, nearly allied to tobacco. They are much prized by horticulturists for the beauty of their flowers. PEWTER. The finer pewter is an alloy of 12 parts tin, one part anti- mony, and a small quantity of copper; the coarser, of 80 parts tin and 20 of lead. The same ingredients as the finer pewter, but in different proportions (nine of tin to one of antimony) constitute Britannia metal. Pewter is a name also for a polishing material used by marble workers and derived from the calcination of tin. PEZET, FEDERICO ALFONSO, a Peruvian diplomat. He was born in London, England, in 1859, and there partly educated, later going to Peru, and serving in the war with Chile. In 1886 he became consul at Panama, and later in England and New York. He was Minister Plenipotentiary to Panama in 1909, and from that year to 1912 special envoy to Central America and Panama. In 1912 he became minister to the United States. His books include : "Peru: Its Commerce and Resources"; "The Question of the Pacific"; "What the Panama Canal Means to Peru." PFAFERS, hot springs in the canton of St. Gall, Switzerland, in the deep and gloomy gorge of the Tamina torrent, which joins the Rhine at Ragatz, 2V^ miles to the N. They were discovered toward the middle of the 11th century, and have been used ever since. The wa- ter is conducted in pipes to Ragatz, though there are bath houses (1704) in the ravine. Near the village of Pfafers, which stands above and outside the ra- vine, is a Benedictine abbey, founded in the 8th century, but converted into a lunatic asylum after its dissolution in 1838. PFENNIG, or PFENNING, a small copper coin of various values, current in Germany and the neighboring states. The pfennig of the German empire is the hundredth part of the mark.
