152 Pomological Notices. 



in a state of motion. The motion produced by a large surface 

 of radiation, by hot water pipes, or common flues, may be 

 imperceptible to the casual observer, but it is not the less 

 real ; and as the amount of heat diffused is just equal to the 

 amount carried off by radiation from the glass, (providing the 

 internal atmosphere be kept at a given temperature,) so must 

 this imperceptible motion continue as long as any difference 

 exists betwixt the internal and external atmospheres. 



There have some other, though less important, argu- 

 ments been used to support the sinking reputation of Pol- 

 maise for the heating of plant houses ; and as drowning men 

 eagerly catch at straws, it is not surprising that its theoretical 

 advocates should clutch at some vague and shadowy princi- 

 ple of science, just to keep the subject which they have ag- 

 itated, before the public, and probably to gain themselves a 

 little notoriety. The learned editor who threw down the 

 gauntlet to the opposers of Polmaise, has more than once 

 had his theoretical whimsies exploded by the stubborn facts 

 of practical experience ; and, as many persons in this country 

 eagerly follow any crotchety notion they read in the Gar- 

 deners^ Chronicle, taking the reputation of its editor as a 

 guarantee of its truth, I purpose to devote a few papers to 

 this subject, drawn from the best of all sources, — practical 

 experience. 



Clifton Gardens, near Baltimore, Feb., 1850. 

 ( To he continued. ) 



Art. II. Pomological Notices; or Notices respecting new 

 and superior Fruits, worthy of general cultivation. By 

 the Editor. 



Owing to the unpropitious season for fruit last year, we 

 are not enabled to render our pomological notices as interest- 

 ing as usual ; with the exception of the Beurre Langelier, 

 and two or three others, scarcely a new Pear fruited last 

 year, in the numerous amateur and nursery collections in the 



