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LI. On blacking Garden Walls. In aLetter to the Secretary. 

 By Mr. Charles Harrison, F. H. jS. Gardener to James 

 Archibald Stuart Wortley, Esq. F. H. S. at Worthy 

 Hall, in Yorkshire. 



Read March 21, 1826. 



Sir, 



The blacking of Garden Walls, particularly when they are 

 not flued, is so beneficial to the fruit trees trained on them 

 in this cold part of the kingdom, that I most cheerfully 

 comply with your request of sending to the Horticultural 

 Society an account of the manner of putting on the colour as 

 practised by me, as well as of stating the advantages which 

 the plan affords. 



When the leaves have fallen in the autumn, I take the 

 earliest opportunity to loosen the trees from the wall and to 

 prune them ; the wall is then coloured with coal tar, mixing 

 with every gallon of the tar one pint of linseed oil, in order 

 to prevent it having a shining surface when dry. It is more 

 necessary to make this addition in hotter parts of the king- 

 dom than it is here, but even here it is essential in hot sum- 

 mers, for when the sun shines strongly on the wall with a 

 shining black surface it has appeared to me to scorch those 

 shoots which touch the wall ; but this does not happen when 

 the colour is rendered opaque by the mixture of the oil as 

 recommended. If the wall had not been previously coloured I 

 give it a second coat as soon as the first is dry. In laying on 

 the colour care is taken that the liquid is not sprinkled upon 



