154 abstracts: physics 



It is suggested that a greater prevalence of cirrus clouds in the equa- 

 torial regions than in other parts of the world (and observations indicate 

 this inequality in their distribution) would largely account for the change 

 with latitude of the temperature and height of the isothermal region. 

 These clouds, whenever and wherever present, must act as a shield and 

 partially protect the outer atmosphere from the radiation of lower levels, 

 and thus allow it to grow colder through its own radiation to space. The 

 somewhat entrapped heat below the tropical cirri must expand the atmos- 

 phere and thus increase its horizontal flow to higher latitudes where 

 presumably there is less cirrus and freer direct radiation from the denser 

 and lower atmosphere, and hence a warmer isothermal region. 



W. J. H. 



PHYSICS. — Recent advances in high-temperature gas thermometry. 

 Arthur L. Day. Trans. Faraday Society, London. 7: 1911. 

 An address before the Faraday Society of London, reviewing the more 

 important features of the recent work with the gas thermometer con- 

 ducted at the Geophysical laboratory. 



PHYSICS. — The detection of small heat effects at high temperatures. 

 Walter P. White, Geophysical Laboratory. Physical Review, 

 32: 604. 1911. 



The general principle of the method is simple and fairly familiar. No 

 moving bodies are present, and changes in the temperature of the charge 

 are brought about solely by changing the furnace temperature. The 

 heat effects in the charge are inferred from the changes in its tempera- 

 ture. The temperature of the charge thus depends upon two things: 

 first, the furnace temperature, and second, the heat effects in the charge. 

 The manipulation consists in observing the temperature rise, regulating 

 the furnace current accordingly, and observing the temperature differ- 

 ence of furnace and charge. 



The interpretation of the results may, in theory, be made very simple. 



The temperature gradient, G, between charge and furnace, serves as 

 the measure of heat-flow to the charge. The flow actually is propor- 

 tional to G, and to the heat-transmittance, F, of the space between fur- 

 nace and charge. The exact values of both G and F are usually unknown, 

 and may vary with time, temperature, rate of heating, etc., so that accu- 

 rate heat determinations by means of them, tho possible, are quite 

 difficult. But in the detection of a small heat effect we have merely to 

 determine the change in G caused by the addition of the effect to the 

 heat which is required to change the temperature of the charge. For 



