694 CURRENT TOPICS. [J. F. I.

Magnetic State of Prehistoric Burned Earths. P . L . ~'[ERCAN- TON. (Bull. Soci~td lZandoise, vol. lii, No. I94 . ) - -The author is continuing the investigations of the Italian, Folgheraiter. When pottery was baked or lavas cooled they assumed in many cases a magnetic state depending upon the direction of the earth's mag- netic field at the time. If the position which they occupied while cooling can be determined, it is sometimes possible to infer the direction of the earth's magnetic field after a magnet- ometric investigation of the object. M. Mercanton reports in this paper the results of his examination of eleven pieces of baked clay, used as sinkers in fishing. He finds no regularity of magnetization and concludes that all were baked at a time when the earth's field was horizontal, i.e., when the inclination was zero. He is surprised at this, since the sinkers come from vari- ous ages, such as the stone, and the bronze age.

G. F. S.

Signal Corps School.--Realizing that there are comparatively few trained radio operators available, to fill the needs of the Signal Corps, the Government has established a training school at Camp Alfred Vail, New Jersey. Here men with only common school education can be sent from the enlisted personnel and secure a thorough training in signal corps specialties. These in the main are the same as one meets in civil life, with the addition of their military application. Men will be trained as telegraph, tele- phone and radio operators; electricians, instrument makers and repairers; cane splicers, cooks, clerks, photographers; chauffeurs and motorcyclists.

The location of this school at Camp Vail, N. J., will be con- sidered as temporary until the extent of the needs of the Army with reference to permanent Signal Corps Schools has been defi- nitely determined and approved by the War Department.

Passenger Train Resistance. (University of Illinois, Engi- neering Experiment Station, Bulletin zIo, I9Z9.)--Tests to deter- mine the resistance of passenger trains at all speeds up to seventy miles per hour, and for average car weights have been completed by the Railway Department of the Engineering Experiment Station of the U~niversity of Illinois. Of the 240 cars composing the 28 trains tested, I78 had six-wheel trucks, and 62 had four-wheel trucks. These tests were made on the lines of Illinois Central Railroad by Professor E. C. Schmidt and H. H. Dunn upon well constructed and well maintained main line track laid almost en- tirely with 85-pound or 9o-pound rail and ballasted with broken stone.

From the rest~lts, which are given in Bulletin No. IIO of the Engineering Experiment Station, a table has been prepared show- ing the probable average value of resistance for passenger trains composed of cars weighing from thirty to seventy tons and oper- ating at speeds ranging from five to seventy-five miles per hour.