I860.] 



THE SOUTHEEN PLANTER. 



503 



pansion of the air which exists in the inter- 

 stices between them, while at night they be- 

 come cooler by radiation than the surround- 1 

 ing air, and tend to condense upon them- 

 selves the neighboring moisture, and conse- 

 quently to sink to a lower level. It is on 

 this account that the smoky clouds which 

 are produced by the enterprising manufac- 

 turing establishments of Pittsburg and other 

 Western cities, in still weather, sometimes 

 descend to the surface of the earth, and en- 

 Telop the inhabitants in a sable curtain more ( 

 indicative of material prosperity than of do- \ 

 mestic comfort. From the density and the 

 wide diffusion of these smoky clouds they 

 must produce a sensible effect upon the tem- 

 perature of the season of the year in which 

 they occur. During a still night, when a 

 cloud of this kind is over head, no dew is 

 produced ; the heat which is radiated from 

 the earth is reflected or absorbed and radia- 

 ted back again by the particles of soot, and 

 the cooling of the earth necessary to pro- 

 duce the deposition of water in the form of 

 dew and hoar frost is prevented. 



So well aware of this fact are the inhabi- 

 tants of some parts of Switzerland that, ac- 

 cording to a paper by Boussingault, in a late 

 number of the " Annales de Chimie/' they 

 kindle large fires in the vicinity of their 

 vine fields and cover them with brush to pro- 

 duce a smoke-cloud by which to defend the 

 tender plants from the effects of an untime- 

 ly frost. Though the first announcement of 

 the proposition by some of our earlier me- 

 teorologists, that the peculiar condition of 

 the atmosphere known as Indian summer 

 might be produced by the burning of the 

 prairies, was not thought worthy of any 

 comment, yet the advance of science in re- 

 vealing the facts I have stated renders this 

 hypothesis by no means unworthy of atten- 

 tion. 



A large amount of smoke existing in the 

 atmosphere must have a very sensible effect 

 in ameliorating the temperature of the sea- 

 son by preventing the cooling due to radia- 

 tion ; and although this may not be the sole 

 cause of the peculiarity of the weather we 

 have mentioned, it may be an important 

 consideration in accounting for the smoky 

 appearance of the air, and the effect produ- 

 ced upon the eyes. 



In concluding this section, we would com- 

 mend to the attention of the microscopists 

 of this country, as a readily accessible and 

 interesting field of research, the subject of 



atmospheric dust. The atmosphere con- 

 stantly holds in suspension a mass of parti- 

 cles derived from the mineral crust of the 

 globe and from animals and vegetables, 

 which, by being deposited in undisturbed 

 positions, serves as a record to be read by 

 the microscope of changes alike interesting 

 to the antiquarian and the naturalist. On 

 this subject, M. Pouchet ha^ lately present- 

 ed a paper to the French Academy of Sci- 

 ence, in which he enumerates the particles 

 (Of mineral, animal and vegetable origin, 

 i which he has found deposited from the at- 

 mosphere. Under the latter he mentions 

 specially particles of wheat flour which have 

 been found as an ingredient of dust in 

 tombs and vaults of churches undisturbed 

 for centuries. The dust floating in the at- 

 mosphere may readily be collected by filter- 

 ing the air through a tube swelled in the 

 middle, bent into the form of a syphon, par- 

 tially filled with water and attached at the 

 lower end to the vent-hole of a cask from 

 which water is drawn, or simply by sucking- 

 through the air by means of the mouth. 

 Prof. He?irij in Patent Office Report of 185S. 



Fo7- the Southern Planter. 



The best Time for Closing the Agricul- 

 tural Year. 



Mr. Editor : —At your earnest request to 

 Farmers, in the June number of the Planter, 

 to write something, I have concluded to pen 

 a few of my thoughts, which, if you think 

 fit, you can give a place in your paper. I 

 think I can make a suggestion Or two, that 

 no one will hardly controvert, and but few, 

 who will think for a moment, can fail to see 

 the utility of. It is this — the expiration 

 of the Farmer's year : I am sure the first of 

 December will suit us much better than the 

 first of January — certainly as to the change 

 of overseers and hired servants on the farm. 

 When an arrangement has been made for 

 an overseer to change his home, the sooner 

 he can leave, after carefully housing the 

 crop and seeding the wheat, the better for 

 himself and his employer, as well as for 

 his successor and his succeeding em- 

 ployer. The overseer has, what is of 

 importance, if he is a married man, better 

 weather and better roads generally for mov- 

 ing his family; he gets to his new home 

 and makes some start for his succeeding 

 crop before Christmas, and is there during 

 the holidays to attend to the stock and ser- 

 vantS; and other things about the farm that 



