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CREOSOTING TIMBER.
Everybody has had the toothache; consequently, everybody knows what creosote is. Very few people are, however, aware that the clear, watery-looking spirit with which they have vainly scorched and blistered their gums is, though in a different form, a cure for all the ills which wood is heir to.
From the days of Pliny downwards, all manner of ideas have been suggested, and all manner of efforts made to prolong the natural duration of timber, by enduing it with an artificial power of resistance to its foes. Lime, salt, corrosive sublimate, and countless other chemical agents have been infructuously tried; their use did not appear to add one single year to the evanescent lives of poles and rafters. Dry rot and wet rot, ants and worms, were as destructive as ever, and there seemed to be no prospect of bestowing on timber the immortality so much desired for it.
In 1839, a patent was obtained, by Mr. John Bethell, for preserving wood, by injecting into it oil of tar, commonly known as oil of creosote, from the quantity of that spirit which it contains: the experience of thirteen years appears to prove that the long-sought discovery has at last been made. In the Great Exhibition last year, attested average specimens of creosoted timber were shown, which positively were, after ten or twelve years' constant use, as sound and solid as when they were first put down; while in immediate and most suggestive comparison with them were pieces of undoctored wood which, after one-third of the saem sort of service as their pickled neighbours had performed, presented the external similitude of pulverised hay, or shrivelled honeycomb. Mr. Bethell's invention was mentioned, with strong commendation, in the Jurors' reports, and a prize medal was awarded to him for it.
The so-called "creosote," employed in this process of embalming wood, is one of the products obtained by distillation from common coal tar. It is a thick, dark brown oil, rather heavier than water, with which, of course, it will not mix. It is not quite the sort of stuff which one would like to put into one;s mouth, even in the delusive hope of curing pain. The spirit which the chemists sell by the same name is distilled, with much more care and elaboration, from a different material.
Mr. Bethell's principal works near London are at East Greenwich. They have a wharf frontage to the river, for the reception of the raw timber, which is brought alongside in barges, and is landed and piled into stacks until its turn comes for undergoing the treatment which is to bestow upon it everlasting youth. The timber consists of railway sleepers, piles, telegraph posts, and other articles for use in the open air. Palings, pit-props, and hop-poles, are often sent to be preserved, and the process as even been tried upon waste fish, for use as manure.
In the middle of the works stand, or rather lie conspicuous, side by side, two immense wrought-iron cylinders, each seventy feet long, and six feet in diameter inside; with doors at one end, and a tramway running from the river side right into each. Next to them is a brick "drying house," with ovens and flues for drying and smoking the wood. Some large, open, iron tanks, a steam-engine, and a saw -mill, complete the machinery of the establishment.
