oct.— dec. 1857.] Mode of protecting Timber from Fire. 129 



The durability of the coating was tested by exposing prepared 

 surfaces of wood to a continuous stream of water, and to heavy 

 rains, for a considerable period. It was found that the rain had no 

 effect upon the coating ; in the other more severe test, the mate- 

 rial was only to some extent removed, after a time, on that spot 

 where the jet of water first impinged upon the wood. 



A trial was made of the firmness of the coating, by applying 

 heavy blows to the surface of the wood ; the covering was only dis- 

 turbed in one or two places, where the lime had been laid on rather 

 too thickly. 



The stove was placed in a prepared corner of the hut, at a dis- 

 tance of about 10 inches from the sides, and the fire was speedily 

 raised to a sufficient degree to render the sides of the stove red 

 hot in several places. 



About one hour and a quarter elapsed, after the stove was well 

 alight, before those portions of the sides nearest to the hottest parts 

 of the fire evinced any sympton of igniting, although the wood was 

 scorched, and to a great extent baked, in several places : those por- 

 tions becoming at last so hot on the outside, that the hand could 

 j scarcely be placed against them. 



At this point, the prepared side which had been painted, became 

 ignited, the vapours emitted from it, by the baking of the wood, 

 being very considerable. The remainder of the heated corner in 

 flamed instantaneously, but the flame was not so powerful as that 

 covering the painted portion. 



After the first burst of flame from the prepared planks, produc- 

 ed by trie ignition of the vapours baked out of the wood, the fire 

 went down considerably and made but very little progress. Now 

 and then a small burst of flame was seen on the outside, issuing 

 from between the joints of the weather-boarding, but it was soon 

 evident that the fire could only with great difficulty seize perma- 

 nently on the prepared surface of the wood, and that it only spread 

 very slowly by creeping along between the overlapping portions 

 of the planking, which were unprotected, and between the quarter- 



