1 80 General Notices. 



Academy which are sufficient when the interest of science alone is in question. 

 They have thought that in a matter of public interest, in which our marine, 

 our public works, and our arts are so highly interested, in which our agriculture 

 will find new interest in the restoration of those forests so unfortunately 

 destroyed in some parts of France, something more was necessary than a 

 mere mark of approbation. They propose to the Academy, therefore, to 

 decide : — 



" 1st. That M. Boucherie's memoir should be placed in the collection of 

 works by foreign savans, which it well deserves. 



" 2dly. That a copy of this report be transmitted to the Ministers of 

 Agriculture and Commerce, of Public Works, and of the Marine, Finances, 

 and War." 



The resolutions of this report were adopted. (^Le Temfs, Dec. 3. Com- 

 municated by G. G., Dec. 10. 1840.) 



On a Method of Prognosticating the proiahle Mean Temperature of the 

 several Winter Months from that of corresponding Months in the preceding 

 Summer. — A paper was read on this subject by Mr. Graham Hutchinson, at 

 the meeting of the British Association at Glasgow. " From the slowness 

 with which the increased temperature of summer penetrates the surface of the 

 ground, Mr. Hutchinson thought it probable that the last portion absorbed 

 during the summer half of the year, and which descends to the least depth below 

 the surface, should be the first portion given oiF during the winter half ; and, 

 in like manner, that the first portion absorbed during the summer half, and 

 which must descend to a greater depth below the surface than any other 

 portion, should be the last to be given off during the winter half. And though 

 the diffusive tendency of caloric, and the variations of temperature arising 

 from alterations in the direction of the wind, &c., may render it impossible to 

 predict within a week when the first, the last, or any other portion of the 

 summer's heat is absorbed or given off by the earth's surface, still, by em- 

 bracing a period of longer duration, such as a month, we may, on an average 

 of years, come somewhat near the truth. Agreeably to the principle above 

 stated, the months in which an absorption of heat takes place should have 

 corresponding months of retrocession, or some approximation thereto ; and, 

 consequently, the mean atmospheric temperature of any month in the summer 

 half of the year would afford a means of prognosticating the mean lempe- i 

 rature of its corresponding month in the winter half of the year, so far at ; 

 least as that mean atmospheric temperature depended upon the retrocession : 

 of heat absorbed during the previous summer half. For facility of com- 

 parison, the two equinoctial months, September and March, were left out of j 

 consideration. The corresponding months of temperature, then, are as < 

 follows ; — 



August has October following"] 



June December I for its corresponding month of 



May January j temperature. 



April February J 



" If, for example, August be warmer than average, the mean atmosphericj 

 temperature of October following should likewise be warmer than average. 

 From tables then referred to, Mr. Hutchinson said it appeared that, in Scot-J 

 land, deviations in the mean temperature of the summer months have a visible] 

 influence in producing like deviations of temperature in their corresponding! 

 months in the subsequent winter half of the year. It appeared, also, that, inl 

 the generality of years, the other disturbing causes, which diversify the tem-j 

 perature of the same winter months in different \'ears, such as variations in! 

 the direction and force of the winds, &c., have less influence when averagedi 

 for a month than we should be apt a 'priori to suppose. Antl when the samel 

 months, for a number of years, are grouped together and compared, as was! 

 done in the tables, the disturbing causes, which may occasion a great deviation! 

 from the mean temperature in any particular month in one year, seem partiallyl 

 to neutralise each other, and render the influence of unusual warmth orj 



