S6 Dr. Bottomley 07i the late 



state of a true vapour, although on the other hand the invisi- 

 bility in the atmosphere under ordinary circumstances, in 

 the form of cloud or fog, renders it difficult to suppose that 

 it can be in the ordinary liquid state. If the vapour brought 

 by a rainy wind retains its latent heat up to the moment 

 that actual precipitation of rain takes place, the sudden 

 disengagement of the heat, although occurring in the 

 higher regions of the atmosphere, ought to have a very 

 sensible effect in raising the mean temperature of rainy 

 days, but no such effect is produced. To account for the 

 enormous quantity of heat given off by the vapour which 

 is condensed in the atmosphere, he thinks that it is probable, 

 that air nearly saturated with vapour has a greater power 

 of radiating heat than dry air. The unusual transparence 

 of the atmosphere often observed immediately before, and 

 even during showers, is probably due to its being charged 

 with vapour which has lost its latent heat. " Observations 

 of the Oblique Belt on Jupiter." 



Session 1 860-61. — " Phenomena of Solar Spots"; "On 

 a System of Periodic Disturbances of Atmospheric Pressure 

 in Europe and Northern Asia." In an enquiry of this 

 kind he states that determinations of the statical element 

 of mean pressure are obviously of very limited use, 

 but notwithstanding the importance of the subject, 

 meteorologists have hitherto generally neglected to ascer- 

 tain even approximately the value of the dyna7nical 

 element as represented by the extent and frequency of the 

 oscillations of the mercurial column. He gives tables 

 showing the mean monthly and annual sums of the oscilla- 

 tions of the barometer at seven stations in Europe and six 

 in Asia, derived from observations extending over periods 

 varying from six to fifteen years. He remarks that the 

 full application of the method employed appears to have 

 been made by Dr. Dalton in his meteorological essays. — 

 '' Note on the Phenomena of Solar Spots." From some data 



