The principal building material which causes the destruction of our houses by fire is wood—combustible wood. If, therefore, (as nearly all our houses are “brick and timber” erections,) we render this wood uninflammable, what will the cost be?
The following is an approximate estimate of the extra expense, including sundries, &c.:—
| Timber and Deals. Loads. | Cost of House. £ | Additional expense. £ |
|---|---|---|
| 25 | 1000 | 34 |
| 15 | 600 | 21 |
| 10 | 400 | 14 |
| 8 | 250 | 12 |
When will the Building Act compel us to use this table in daily practice?
Although among the many attempts to preserve wood those in England have proved the most successful, it should be mentioned that France, Germany, and America have given much attention to the subject.
At the end of the last century Du Hamel and Buffon pointed out the possibility of preserving wood, as well as the means of rendering it unalterable. As early as 1758 Du Hamel made experiments on the vital suction of plants, and made some curious observations on the different rings of vegetable matter which absorb most liquid in different plants. He also tried the effect of vital suction and pressure (of gravitation) acting at the same time. His process was reviewed by Barral in 1842.
About 1784 M. Migneron invented a process about which little is now known, but the wood was covered with certain fatty substances. Wood nine years exposed to deterioration was improved by this process. M. Migneron had the approval of Buffon, Franklin, and the Academies. His invention was again brought into notice in 1807, when it was found that timber which had been prepared by it in 1784, and exposed more than twenty years, was quite sound.
In 1811 Cadet de Gassicourt made different kinds of wood imbibe vegetable and mineral substances, and certain unguents: he used metallic salts (iron, tin, &c.).
In 1813 M. Champy plunged wood into a bath of tallow at 334°, and kept it there two or three hours. His experiments were afterwards repeated by Mr. Payne.