70 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



TEMPERATURE AND DIATHERMANCY. 



Our knowledge of the transparency of our atmosphere is 

 reviewed by liicco in the Memoirs of the Italian Spectro- 

 scopic Society; he gives an instructive collation of the co- 

 efficients of transmission of the total solar radiation and 

 also the separate coefficients for the purely luminous rays. 

 Some observations made by Provenzali at Rome with the 

 lucimeter are here published for the first time. 



Numerous papers relative especially to the diathermancy 

 of the atmosphere have been published in France principal- 

 ly by Crova. 



Wielenmann's important memoir of 1872, on the tempera- 

 ture of the atmosphere as deduced from purely geometrical 

 and physical relations, and in which he successfully repro- 

 duced the observed hourly temperatures for stations over 

 the whole globe, has now been followed by an almost equal- 

 ly successful deductive treatment of the subject of evapora- 

 tion and atmospheric moisture. A translation by Freeman 

 of Fourier's "Analytical Theory of Heat" has been pub- 

 lished by the Cambridge Press. 



Dr. Stilling, in studying the cold period of May, 1876, in 

 Pussia, shows that it depended on the formation of baro- 

 metrical minima, which passed from the Baltic to Southern 

 Europe. 



Careful observations and study of the temperature and 

 humidity of the air at different altitudes have been made at 

 Upsala by Professor Hamberg. By means of thermometers 

 attached to high stationary posts, Hamberg has studied the 

 influence of altitude per se, while by means of small mova- 

 ble posts he has investigated the influence of the nature of 

 the surface soil. Some of his results are briefly as follows : 

 During clear weather, and at least from two hours before 

 sunrise to two hours before sunset, the temperature of the 

 air is lower than that of the earth on which it rests. The 

 fall in temperature preceding sunset is greater near the 

 earth than at greater heights. The latent heat evolved 

 during the formation of dew arrests the fall in the tempera- 

 ture, but not to the extent that some suppose. After the 

 dew is deposited, the temperature may sink even to below 

 the freezing-point ; but as soon as the dew changes to hoar- 



