Cultivation of oaks. l7 



amounting to 34° .7 (78° of Fahr.) was necefTary In order 

 to depoiit dew. This obfervation alone is fufficient to render 

 his hj'grometer fufpeded; for, few who have attended to the 

 formation of dew will admit the probabilityoffo large a reduc- 

 tion being neceffary in any climate or feafon : I believe it 

 rarely requires 40° reduction in temperature in any part of the 

 world to produce the effed. 



Plate I.* is intended to illuftrate the author^s conception of Engraving to 

 the conftitution of the atmofphere. The different marks or JJj^j^ the conftl- 

 characters of the particles of the gafes are merely arbitrary, atmofphere. 

 and intended for diftinflion; the fimple atmofpheres are given 

 nearly on their real dentities, and the particles are arranged at i 



equal diftances from each other. In the compound atmof- 

 phere the fame arrangement is made of each kind of particles 

 as in the fimple; but the particles of different kinds do not 

 arrange at regular diftances from each other; becaufe it is fup- 

 pofed they do not repel each other. . 



III. 



Obfervalions on the Cultivation and Growth of Oak Timber, In 

 a Letter from the Rev. Richard Yates, F. A. S. Chaplain 

 to His Majefiy^s Royal Hofpital at Chelfea, to Charles 

 Taylor, E/q. Secretary to the Society of Arts \. 



S I R, 



JL O expatiate upon the vaft importance of increafing the Great Impor- 

 growth of oak-timber, feems unneceffary. The national ad- [u"e^of^the oak! 

 vantages refulting from this fource appear to be in general 

 well underftood ; and yet the cultivation and management of 

 this moft ufeful plant has not hitherto obtained jtbat degree of ^ 

 attention which it moft certainly merits. 



Entirely to obviate, or even in fome meafure to remove or 

 leffen, the obftacles that ftill continue to impede the planting 



* From the fame Vol. of the Manchefter Memoirs.— I remind the 

 reader of the references at page 257 of our laft, 



t For which the filver medal was voted. Memoirs for 1802, 

 page 80. 



Vol, VII.— January, 1804. C of 



