14S Scientific Intelligence. 



beautiful sapphire color, and had the same optical properties as 

 the natural mineral. It is remarkable that the oxides employed 

 should give a blue color. — (Jomptes Rendus, cl, 391. h. l. w. 



5. Inflvu nee of 'Temperature on the Compressibility of Metals. 

 — E. Gruneisen's experiments on this subject extended over a 

 range of temperatures of — 190° to 166°. He used a Cailletet 

 pump for high temperatures and bombs filled with hydrogen gas 

 for low temperatures. He, therefore, did not go above a pres- 

 sure of 500 atmospheres. He finds that the compressibility 

 increases with the temperature, or in other words the expansion 

 coefficient diminishes with increasing pressure. Apparently with 

 a linear expansion one must have a linear compressibility. — Ann. 

 der Physik, No. 16, 1910, pp. 1239-1274. 3. t. 



6. Ionization of the Atmosphere due to Radio-active 3fatter. — 

 This subject is of importance in regard to the observed difference 

 between the case of transmission of wireless signals at night and 

 in the daytime. A. S. Eve, McGill University, gives a table 

 which indicates a decreasing ionization with altitude which can 

 be detected at an elevation of 100 meters, and also that at 1000 

 meters the penetrating rays from the earth are ineffective 

 ionizers. — Phil. May., Jan., 1911, pp. 26-39. j. t. 



7. Thomson Effect. — This has been measured by P. Cermak 

 in lead, mercury, tin, zinc, cadmium, and aluminium ; the effect 

 has been found extremely small, but never constantly nothing. In 

 the transition from the solid to the liquid state the curve repre- 

 senting the Thomson effect is a continuous one ; while that repre- 

 senting the change in resistance is a broken one. — Ann. der 

 Physik, No. 16, 1910, pp. 1195-1215. j. t. 



8. Velocity Measurement of Rontgen Rays. — A very volumi- 

 nous paper on this subject has been published by E. Marx. He 

 discusses various method-causes of error; maxima and minima 

 in the bundle of rays, phase differences and other conditions. 

 Various wave lengths were found, which depend so much upon 

 these conditions that a definite wave length is apparently not 

 reached. The paper concludes with a discussion of Bragg's the- 

 ory, corpuscular theory of neutrals and doublets, and the bearing 

 of the impulse theory on the existence of an ether. — Ann. der 

 Physik, No. 16, 1910, pp. 1305-1391. j. t. 



II. Geology. 



1. Osteology of Pteranodon ; by George F. Eaton, Ph.D. 

 Memoirs of the Connecticut Academy of Arts and Sciences, vol. 

 II, pp. 1-38 and pis. i-xxxi, July 1910. — In this volume Dr. 

 Eaton discusses the morphology of the American pterodactyl genus 

 Pteranodon, basing his descriptions upon material in the Peabody 

 Museum of Yale University assembled by Professor Marsh and 

 numbering in all no fewer than 465 individuals. Of this mate- 

 rial but seven specimens, including the types of the three sjtecies 



