carbonising timber by means of inflammable gas (either pure hydrogen, or, better still, lighting gas) directed by means of a tube against every part to be carbonised, just as one would direct a jet of water from a fireengine upon the flame to be extinguished. A trial of it was made at Cherbourg in presence of the Director of Naval Works and numerous other witnesses, and it is said this was crowned with complete success. The absence of all danger from fire was clearly proved, and this of course removed the principal objection to its introduction in the dockyards. The cost, it appeared from calculations made at the gas-meter of the town, with the aid of an accountant, did not exceed one penny per square metre for gas and labour together.
M. de Lapparent holds that, the surface being once thoroughly dried, the juices of the interior will remain inactive, and the durability of the timber be thereby insured.
I experimented with this process at Woolwich in 1862, by charring seven out of twelve pieces of winter-felled British Oak, prepared to a scantling of 2″ × 2″ × 84″ and disposed of them as follows: for instance, Nos. 3, 7, 8, 9, 10, 11, and 12 were carbonised, and Nos. 1, 2, 4, 5, and 6 were not carbonised. Of the former, Nos. 3 and 10, and of the latter, Nos. 1 and 2, were suspended in a dry place in the store room; Nos. 7, 8, and 9, and Nos. 4, 5, and 6, were put into a box of manure; Nos. 11 and 12 were driven half their length into damp earth, on the stacking ground.
