32 



58 



441 



76 



66 



63 



61| 



561 



51 



50 



47i 



421 



53 



49A 



44 



6H 



65i 



601 



60 



561 



5] 



56i 



50 



45^ 



71 



66 



62 



61i 



57* 



521 



55h 



50 



45 



76 



69 



651 



63 



57 



521 



Retrospective Criticism. 379 



Aug. Sept. Oct. 



Sloping brick wall painted black, greatest cold in 



the night 48i° 45° 401° 



At 6 o'clock in the morning, or, as the season 



advances, as soon as clear in the sky 

 At 1 o'clock P.M. - - - - - - 



At 6 o'clock evening - _ - _ _ 

 Perpendicular wall of whinstone, or dark green- 

 stone, greatest cold in the night - - - 

 At 6 o'clock morning - - - - - 



At 1 o'clock P.M. - - - - - - 



At 6 o'clock evening - - - - _ 



Perpendicular wall of freestone, at 6 o'clock 

 morning -_---.- 

 At 10 o'clock P.M. 

 At 6 o'clock evening - - - - - 



Perpendicular brick wall, at 6 o'clock morning - 

 At 1 o'clock p. M. - . _ _ _ 



At 6 o'clock evening - - _ _ _ 



" The sloping black wall is considerably colder in the night than the per- 

 pendicular whinstone wall; for August, H degree on the mean ; for Septem- 

 ber, 21 degrees ; for October, 2 degrees ; it having been those two only that 

 have been compared with the thermometer that indicates the minimum degree 

 of temperature. 



"At six in the morning, the freestone is the warmest; for August, 1 degree 

 warmer than the brick, 4 degrees warmer than the black painted wall, 3i 

 warmer than the whinstone. The brick is the warmest, at one o'clock, of all 

 the kinds. In September, it is 3 degrees above any of the other kinds, 

 the black sloping and freestone being, in that month, 3 degrees lower, and the 

 whinstone 3J degrees below the brick. The differences may easily be ob- 

 served by comparison above." 



The evident greater escape of heat by radiation from the sloping wall dur- 

 ing the night, suggests the idea of having fruit walls furnished with a broad 

 coping, which would be capable of being speedily extended or retracted. It 

 might be also necessary to ascertain what sort of materials are best adapted 

 for preventing radiation ; for instance, wood lined with some sort of woollen 

 material. In dry warm weather, coping of any sort, except what is merely 

 sufficient for protecting the structure of the wall itself, is better dispensed with. 



It is to be hoped that these experiments will be continued by the Cale- 

 donian Horticultural Societ}^, and with the addition of maximum and mini- 

 mum registering thermometers, on the various substances of which their walls 

 are composed. Such might also be compared with others of the same sort 

 placed in the open ground. 



There is not much to be remarked in regard to the fruits noticed in the 

 printed abstract published by this Meeting as having been proved in the 

 garden, farther than that they are well described, and when more and better 

 varieties, of which the collection must contain many, come to be treated in the 

 same able manner, the accounts will be very interesting. — R. May, 1835. 



Art. II. Retrospective Criticism. 



An Index to the First Ten Volumes of the Garde\ier''s Magazine, — I am 

 glad to see, on the cover of your Number for March, that I have not been 

 the only one that has recommended an index to the first ten volumes of your 

 Magazine; and I think, if all your close and attentive readers were to express 

 themselves upon the subject, that the Cornish motto, " One and all," in favour 

 of it would flow in from all quarters. A good thing, once begun, ought to be 



E E 2 



