METEOROLOGY. 227 



regularly advanced till it arrived at a maximum in the year named in the right-hand column, 

 and then it again regularly declined 



1771 minimum. 1779 maximum. 



1784 " 1794 



1799 

 1814 

 1829 

 1838 

 1854 



1806 

 1822 

 1834 

 1846 



The long-continued observations of Mr. Luke Howard, and the elaborate investigations of 

 Prof. Dove, confirm this movement of the mean annual temperature in certain cycles, the 

 duration of which cannot, however, be said to be as yet exactly determined. 



Prognostications of the Weather. 



NUMEROUS meteorological observations have been undertaken recently with a view of ascer- 

 taining whether the popular and generally-received opinions respecting atmospherical phe- 

 nomena have in reality any foundation. The conclusions are, that little or no dependence 

 can be placed upon any of the popular signs or prophecies, and that, in most cases, fair weather 

 predominates even when the prognostications indicate rain. The following table of numerous 

 registered observations on phenomena which are said to indicate either rain or fair weather, 



shows how the result stood: 



No of Followed in 24 h. by 



Observations. Fair or Rain. 



Solar halos 204 133 71 



Lunar halos 102 51 51 



White stratus in valley 229 201 28 



Distance clear 102 61 41 



' Distant sounds heard as if near 45 25 20 



Aurora Borealis 76 49 27 



Colored clouds at sunset 35 2 9 



Dew profuse 241 198 43 



White frost... . 73 59 .., .. 14 



Stable Ventilation. 



IT is very generally supposed, by those who reason on the subject, that catarrhal and other 

 allied diseases in horses are generally due to the unnatural heat of stables. We are fully 

 inclined to admit that much harm may be traced to unduly warm stables, but we must not 

 forget that the horse can endure heat as well as most animals. In the warmest climates he 

 seldom seems to suffer from heat alone, provided he be not confined in stables. Now, so far 

 as mere heat is concerned, we do not suppose that any of our stables are kept at any thing 

 approaching the temperature of those tropical heats, or even summer heats in this country, 

 which a horse can bear with impunity. A horse, in fact, so far as experience teaches, can 

 bear a high temperature alone, and as such ; but can he endure a high temperature and an 

 impure atmosphere? He cannot, without becoming diseased. Now, the coexistence of un- 

 natural heat and bad ventilation are just what we find in very many stables at all seasons of 

 the year. When the season, however, is cold, there is somewhat less danger to be appre- 

 hended from bad ventilation than when the weather is hot; and yet we find that stablemen 

 do not, as a general rule, make these corresponding differences in their ventilating arrange- 

 ments which summer and winter respectively require. We have often, it is true, seen the 

 windows of stables and certain upper air-holes left open. But it is a well-known fact, that 

 cool air enters best and most effectively at the ground-level, and hot air escapes easily from 



