Q6 On the different Species of Dahlia. 



House as well as in Messrs. Lee and Kennedy's garden at 

 Hammersmith, had then been already blasted by the frosty 

 nights, I understand, it remained uninjured, and continued 

 blowing till the middle of November, in great beauty. 



It is necessary to observe that the village of Mill Hill, 

 where I lately resided, is situated upon a high ridge, at the 

 head of two A-allies, in which some of the sources of the little 

 brook, called the Brent, arise ; and the garden, in which these 

 Dahlias were cultivated, is well screened from the weather by 

 high trees ; being rather above the level at which the exha- 

 lations of the adjacent country pass off, the early autumnal 

 and late spring frosts never reach it ; at least they have been 

 so mild during the six years I lived there, as never to have 

 cut off Cucumber Plants, Potatoes, French Beans, and Nastur- 

 tiums, till long after others of the same species had been killed 

 in the vallies. In hoar frosts, the top of Harrow Hill, Bushy 

 Heath, Elstree, and Totteridge, are commonly seen green, or 

 illuminated by the sun, when the rest of the neighbourhood 

 is white as snow, or obscured in a thick fog. The medium 

 temperature of this delightful spot, and I believe of most 

 other grounds equally elevated, during the months of Decem- 

 ber, January, and February, is considerably milder than in 

 any valley, perhaps never less than from 1 to 5 degrees : in 

 extremely severe frosts, the difference is still more apparent, 

 so that when the cold has been down to 12 and 9 degrees of 

 Fahrenheit's thermometer in London, it has only been 20 and 

 16 there ; and this is likewise proved by the more tender 

 exotic plants still remaining in the garden, some of them 60 

 and 70 years old. The common broad leaved Myrtle against 

 a wall there, quickly grew to 6 feet in height without any 



