154 ON BELL POTS. 



much as the light could be partially, or totally excluded, if neces- 

 sary ; and when the plants required air, it might be given by re- 

 moving the glass or other covering from the top (which covering 

 you will perceive from the drawing rests upon a ledge), and this 

 method, I am persuaded, is far preferable to that of raising it up 

 on one side, as is done with the Bell Glass : for the air in the 

 Bell Pot (being close to the earth at the bottom,) cannot change 

 until it becomes specifically lighter, land of course warmer than 

 the air outside ; as this change takes place it ascends through the 

 top, and is succeeded by colder stratas passing down, which is 

 rendered beneficial to the tender plants by the time it reaches 

 them) 



If the Bell Pots are constructed of the kind of materials that 

 Garden Pots usually are, they would be very cheap, as well as 

 useful as above described. I think the best material for the pur- 

 pose, is the fire brick earth, such as Sir F. Foulkes's ornamental 

 vases are made of. 



The sizes given in the sections, will just fit within the top ol 

 each sized London made Garden Pot. They can, of course, be 

 constructed to any form or size. 



An Old Subscriber. 



Pimlko, May, 1835. 



