786 



GLIiANINGS m 13EE CULTURE. 



Nov 



cabbage, etc., by lifting the sash so as to 

 give air when the weather permits, and cov- 

 ering the plants when the weather is severely 

 cold ; for it is well known, that the class of 

 plants mentioned will stand even 15 or 20^ 

 l)elow zero (covered with sash) if they are 

 properly cared for, or gradually accustomed 

 to the cold. Such structures are also quite 

 valuable for poultry. I believe, however, 

 the best authorities on poultry rather dis- 

 courage the use of artificial heat. 



In connection with heat from the earth, 

 it may be well to speak of what has been 

 called " sub-earth ventilation." Of course, 

 our greenhouses, poultry-houses, or buildings 

 for any oilier purpose, kept warm during 

 the winter time, must have constant acces- 

 sions of fresh air. Well, outdoor air is often 

 at a low temperature, sometimes below zero; 

 and this air must be warmed up by some 

 means, else it will lower the temperature of 

 our inclosure. If we warm it up by means 

 of hot-water pipes or steam-pipes, it takes 

 quite an amount of fuel, besides the labor of 

 keeping fires. Well, instead of having a 

 large cellar to warm our body of surplus air 

 to tlie proper temperature, we may have a 

 pipe, or series of pipes, running some dis- 

 tance under ground, below the point where 

 the frost reaches; and the cold air, taken, 

 say, from out in the fields, at a zero temper- 

 ature, becomes warmed up to 55'^, the 

 natural temperature of the earth, in its pas- 

 sage tlirough these pipes, providing the 

 pipes are not too large in diameter, and are 

 sufficiently long. Usually some arrange- 

 ment has to be made to make tlie air travel 

 in the right direction ; and sometimes a sort 

 of chimney a few feet high is put up at the 

 inlet, and this chimney is surmounted by a 

 sort of funnel, or hood, which is kept facing 

 the wind by means of a vane. This starts a 

 current in the pipe ; and the cellar or green- 

 house where this stream of air at 5o'^ 

 empties has an outlet near the roof, to let 

 the warm air escape. I may say, however, 

 that, in practice, during zero weather the 

 air usually escapes fast enough, without any 

 provision for an outlet. The size and 

 length of these sub-earth pipes depend a 

 good deal on circumstances. Some authori- 

 ties reconmiend that they be laid at least 

 eight feet under ground, and run a distance 

 of 200 feet; but as such an arrangement 

 would be quite expensive, many of our bee- 

 3'o be contin 



friends have had very good results by laying 

 a line of common underdraining tile, say 

 three feet deep, and only fifty or sixty feet 

 in length, the tile to be three or four inches 

 in diameter. While this might not raise the 

 temperature of the air during zero weather 

 to fully 55-\ it would probably raise it con- 

 siderably above the freezing-point. Some 

 experiments are needed in this matter. 



In passing out and in Mammoth Cave dur- 

 ing a frosty, wintry night, we began to find 

 that the stream of incoming air felt chilly 

 when we were perhaps an eighth of a mile 

 from the mouth of the cave. In this case, 

 however, the stream of air was very large, 

 and at the dooi- of the cave it blew almost a 

 gale. Sending a stream of cold air down 

 into a well by means of a pipe, and then col- 

 lecting it at the mouth by another pipe, 

 would also answer to remove tlie frost. But 

 if the stream of air passing down is very 

 large, it might have the effect of freezing the 

 water in the well. 



Now, where there are large natural springs 

 coming out of the hillside, we may, by a very 

 simple arrangement, bring large quantities 

 of heat from the earth, and utilize it by 

 conducting the spring water back and forth 

 in open pipes until it has parted with the 

 heat it contains, until its temperature of .55"^ 

 is reduced nearly to the freezing-point. By 

 having these channels protected by a sash 

 we can combine the heat of the earth and 

 the heat of the sun so as to make an excel- 

 lent cold frame for hardy plants, without 

 the use of artificial heat. The spring water 

 may be passed back and forth under the 

 beds. The heat it gives off will operate in 

 the same way as the heat from hot-water 

 pipes, only we shall never be able to get 

 above 55^ without the aid of the sun. This 

 spring water would be just the thing 

 for watering the plants, and such an 

 arrangement can bo made very pleasing 

 to the eye, as well as profitable to the 

 pocket. A little fountain, or several of 

 them, if made so as to throw a small spray, 

 would induce the water to part with its heat 

 still more rapidly than tlie open channels. 

 One of our most successful bee-men in the 

 State of JSHchigan has a spring in the cellar, 

 or cave, wliere he winters Irs bees. The 

 water from this si)ring, flowing through this 

 room, is found a check to keep tlie tempera- 

 ture from running too low. 

 ued Dec. 15. 



