HOW ARE WE TO IMPROVE? 319 



an inch and a quarter — always showed a mean temperature of 

 nearly 6 deg. Fahr. higher than one hung against a black wall 

 under precisely similar circumstances. 2nd. That during 

 the night the difference of temperature shown by these two 

 thermometers was inappreciable. Contrary therefore to 

 the opinions entertained by many persons, it seems to be 

 evident that the walls must be whitened when we wish to 

 give the trees trained against them the maximum amount of 

 heat to be obtained from the particular climate and aspect. 

 Indeed, it is precisely the plan that has already been pur- 

 sued by the fruit growers of Montreuil for Peach trees, and 

 of Thomery for their Vines, it having been frequently re- 

 marked that trees trained against white walls were healthier 

 than those nailed to more or less dark-coloured ones. This 

 result is easily explained, for not only does the lighter colour 

 reflect more heat back to the trees, but by this means they 

 receive a greater quantity of light ; and it is well known 

 how greatly vegetation is stimulated by these agencies. 

 Walls of a light tint are advantageous in another way, for 

 they not only reflect light and heat on the particular trees 

 trained against them, but also on the others in their imme- 

 diate neighbourhood. By abundantly planting the finer 

 winter Pears against walls with a warm exposure and white- 

 washed surface, we may within half a dozen years gather 

 such crops of the really valuable winter Pears as have never 

 before been seen in this country. 



Another improvement must of necessity accompany this, 

 and that is the French method of wiring garden walls. 

 We cannot use nails with concrete and earth walls, and 

 if we could the deliverance from nails would be a great 

 point gained. To me the most lamentable of all garden 

 sights is that of men handling those miserable shreds and 

 nails during winter time, and blowing heat at their fingers 

 and patting their toes to keep up the circulation. Our way 

 of wiring a wall is so expensive and cumbrous that many 

 still prefer the nails, but the French mode of employing a 

 little raidisseur or tightener on each wire, and using very 

 slender galvanized wire, is quite perfect in its way. When 

 adopted with us it will be found to save much time 



