Terrestrial Magnetism and Atmospheric Electricity Volume 14 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1909 Excerpt: ... to vertical earth-air electric currents, the authors make an erroneous statement with regard to the derivation of my results as given in Terrestrial Magnetism, vol. II, p. 17, which they reproduce on p. 208 of their treatise. My figures were not in any way dependent upon Schmidt's investigations. On the contrary they were obtained independently from the same observed or scaled data which Neumayer furnished Schmidt, the line integrals being computed directly from these data and not from those obtained by Schmidt by the application of spherical harmonics. See Terrestrial Magnetism, vol. IX, p. 117, where likewise will be found my latest results as dependent upon the magnetic data of 1840-45, 1880 and 1885; the authors do not appear to have known of this later paper. Further results may soon be given as dependent upon the magnetic survey of the United States and of the Pacific Ocean.--L. A. Bauer. Satterly, John: The amount of radium emanation in the atmosphere.1 The amount of emanation in a given volume of air is expressed in terms of the mass of radium which would be sufficient to keep up the supply of emanation, the radium and its emanation being supposed to be in radioactive equilibrium. The principle of the experiment was to measure the emanation in a known volume of air and then to measure by the same means the emanation given off from the solution of a known quantity of radium salt in a known time. Two methods were used for collecting the emanation--absorption by charcoal, and condensation by liquid air. Cocoanut charcoal, which absorbs the emanation almost completely and gives it up when heated, was pulverized and packed in porcelain tubes between asbestos plugs and air was drawn through at a constant, measured velocity by means of a filter pump, bein...