ON PREVENTING THE DECAY OP WOOD. S3S 



ft premium from the London Society of Arts*. However just 

 the general principle in this case may be, the application is 

 somewhat unphilosophical; unless it shall be found, which 

 will scarcely be admitted, that dust of every chemical and 

 mechanical quality will equally or sufficiently answer the in-, 

 tended purpose. 



Some material of this kind, selected with greater^ pre- Perhaps fine 

 cision, may however undoubtedly be useful ; and none I *[J e pre er " 

 think promises more fairly than siliceous or flinty sand, 

 which, so far as we know, is absolutely indestructible, and 

 which may be easily procured from the sea-shore, and from 

 the currents of the clear rivers and roads in Berkshire and 

 other counties abounding with siliceous stones. Sand from 

 the sea must first be cleared from all saline impregnations 

 by washing in several waters ; and any sand may be ob- 

 tained of the fineness desired, by mixing it with water in a 

 , tub, and after having stirred the whole well together, 

 pouring out, in a longer or shorter time, the muddy water, 

 from which the sand will settle by its own gravity, in a state „ 

 fit for use when dried. 



More than thirty years ago this subject presented itself to Water-shoots 

 my mind, on seeing some water-shoots, which had been 

 pitched and painted in the common way, taken down in a 

 state of complete rottenness. I had read that charcoal, bu- 

 ried in the moist earth, had come down to us perfectly 

 sound from the times of the Romans ; and that posts long 

 withstood the same moisture, if the part intended to be put 

 into the ground was charred all round to a certain depth. 

 Impressed with these facts, I determined to try an arti- Covered with 



final coat of charcoal; and when new water-shoots were J?"! 5 oll » an '! 



tins dusted with 

 constructed, I strongly and carefully rubbed them with a charcoal. 



coat of drying oil, which I immediately dredged all over 

 with a thick layer of charcoal finely powdered, and con- 

 tained in a muslin bag. After two or three days, when the 

 oil was thoroughly dried, and firmly retained the greatest 

 part of the charcoal, I brushed oft' what was loose, and 

 over that which adhered I applied a coat of common lead- 

 coloured paint, and a few days after, a second. The 



* See Journal, Vol. XIV. p. 258. 



whole 



