USEFUL PROJECTS. 



867 



batanists, as appcai-s from their 

 publications ; but they are know b 

 to the Germans, who have habi- 

 tually used more wood in their 

 buildings than we have. 



I had lately a conversation with 

 an old irientl, who shewed me two 

 parcels of rotten wood, from an oak 

 barn floor, laid about sixteen yeai-s 

 ago. After lying twelve years it 

 shook upon the joists. On exami- 

 nation, it was found to be rotted in 

 Tarious parts, and the planks, two 

 inches and a half in thickness, were 

 nearly eaten through, though the 

 outside was glossy, and without 

 blemish. The joists and a large 

 middle beam were laid at the ends, 

 in brick and mortar, to create a 

 firm level. No earth was near the 

 wood ; and he thinks that no air 

 <:ould find a passage. The rotten- 

 ness was partly an impalpable 

 powder, of the colour of Spanish 

 snuff, and other parts were black, 

 as if burnt ; the rest was clearly a 

 fungus. This gentleman is a per. 

 •son of undoubted veracity, but a 

 nice and exact observation is ne- 

 cessary in such examinations. He 

 thought nothing of any plant, and 

 it is likely there was none of tJic 

 boletus; so that my assertion, that 

 it was always to be found, was rathex 

 too systematic. 



I asked him if the timber was 

 dry when laid down, he could not 

 however say that it had been ])ar- 

 ticularly adverted to. It had been 

 sawed from a large oak, and was, 

 as bethought, in all respects proper 

 for a barn lloor. As this seems 

 not the operation of the boletus, 

 kow did it happen ? 



Wc know that the oak, when in 

 vegetation, is subject to what 1 siiall 

 call an exudation of juices, which 

 produce* the fungus, named the 



agaric of the oak, with which the 

 druids of old played many tricks. 

 The oak then, if sawed into thick 

 quantities, may emit these same 

 juices, as the progressive course of 

 nature to its entire decay. 



AVe have all seen oaks of vast siza 

 and ancient record, with a great 

 part of the outside whole, and all 

 the inside gone ; perhaps the work 

 of a century. In all hollow trees 

 fungus is discoverable. To use a 

 law term, it is a misnomer to call it 

 dry rot; for the rotting principle is 

 in moisture. 



I had never seen tJie rot upon so 

 large a scale as in timber, till lately. 

 The prevention then of beams, 

 rafters, large joists, and posts put 

 into the earth, from decay by the 

 xot, is in charring only, which will 

 dry up all the fungus juices of 

 wood in large substance. Paint, a 

 betumenous preparation, may pro- 

 bably stop up t!ie pores, and pre- 

 vent the rot in slight work, where 

 the trtatment I before observed, 

 with fire, might be incommodious, 

 as in half inch wainscot, &c. The 

 incorruptibility of charcoal is at- 

 tested by undoubted historical 

 facts, at the destruction of the fa- 

 mous temple at Ephesus^ It was 

 found to have been erected on piles 

 that had been charred ; and the 

 charcoal in Ilerculaneum, after 

 almost 2000 years, was entire and 

 undiminished. 



Mr. linimhi/'s cojinniniicaiion. 

 As the society for the encourage- 

 ment of arts, &c. have for some 

 years offered a pretnium for the dis- 

 covery of the cause occasioning tho 

 dry rot in timber, of which itseenii 

 no salihfai lory account !kis ycthccn 

 received ; should (he following prove 

 so, it will give the author much plea- 

 3 K 2 . sure. 



