INDUSTRIAL PROGRESS DURING THE YEAR 187G. xxxiii 



repeated twirling of which within the tube agitates the mercury 

 and dislocates any bubbles of air. 



Professor Kedzie, of Lansing, Michigan, has made a series of ozone 

 observations, which are published by the State Agricultural College. 

 He recommends that such observations be continued, and gives 

 the necessary directions. The subject is one which observers will 

 not consider to have been satisfactorily settled even by the adverse 

 decision of the Vienna Congress and eminent specialists. 



Mr. Scott, of London, communicates to the Meteorological Society 

 some observations, showing that, on the average, the French " Ther- 

 mometre Fronde," or whirling thermometer, is not a very decided 

 improvement upon the ordinary fixed thermometer, when the latter 

 is properly sheltered from radiations. 



Marie Davy has published, in the Bulletin of the Observatory of 

 Montsouris, full details of all the special apparatus employed there 

 to study the physics of the atmosphere, by which is especially meant 

 the study of the part played by aqueous vapor, both visible and in- 

 visible. 



Bosanquet publishes two papers on the " Polarization of the 

 Light of the Sky." This obscure subject received, in 1805, a new 

 interest from TyndalFs observations on the delicate blue colors 

 and polarized light of finely divided vapor. Bosanquet has now for 

 the first time shown the full bearing of these observations upon the 

 Subject of atmospheric polarization. He shows that the diminution 

 of the maximum polarization from zenith to horizon may be regarded 

 as due to a small increase in the mean size of the particles. Except 

 in so far as modified by this circumstance, the phenomena observed 

 in the sky should be arranged symmetrically about an axis drawn 

 toward the sun, and the neutral points of Brewster and Babinet 

 become merely special points in a neutral circle about the sun, while 

 the neutral point of Arago belongs to a similar circle about the ante- 

 solar point. Within these small circles the polarization is negative, 

 except at their centres, which ought theoretically to be the only 

 neutral points in the sky. It is hoped that these diflScult but valu- 

 able observations will receive the attention they deserve on account 

 of their bearing upon the moisture of the air. Bosanquet has in a 

 second memoir, published in the Philosophical Magazine^ given a 

 method of constructing a polarimeter especially adapted to these 

 delicate observations. 



Great interest has been excited by the ingenious radiometer in- 

 vented by Mr. Crookes. Some meteorologists in Europe have, we 

 believe, undertaken regular observations with the instrument, in 

 hopes of obtaining thereby a measure of the total radiation of the 

 sun. In this, however, we presume they are doomed to disappoint- 

 ment, rince it seems to have been abundantly demonstrated that the 

 rotation of the disks is due to only a small portion of the solar radia- 



