Page:Popular Science Monthly Volume 15.djvu/546

530 in which, in one part or other of almost every log, you will not see the beginning of this rot, either as reddish, discolored spots, which, when scratched by the nail, show that the texture to some little depth has been reduced to powder, or else the white fibers themselves may be seen growing. If the cargo was shipped dry, and had a rapid passage, the case is not so bad; but when shipped wet, and the voyage has been prolonged, white fibers will be seen growing over nearly every part of the surface of every log, especially if they are of yellow pine, red pine, and oak.

When deal (pine planks) is shipped wet in Canada, it is also covered with a network of white fibers on its arrival in England, and even when shipped tolerably dry the fungus will be found upon some of the pieces. When they have been floated down our rivers and shipped as soon as they were taken from the water, at the end of the voyage they are often so covered with this network of mycelial fibers that force is necessary to separate them, and they will grow together again in the barges before being landed. If deals in this state are piled flatwise, a whole pile will become deeply affected with rot in six months. In some instances the rot penetrates to the depth of one eighth of an inch. The decay may be arrested by sweeping the surface of each deal, and repiling them upon their edges during dry weather. The ships which carry this timber, though built of good, sound, well-seasoned oak, must be carefully dealt with, or they will become affected. It is usual to scrape their surface as soon as they are clear of the cargo, and sometimes the hold is washed with a desiccating fluid. The effects of dry rot upon European deals are very similar to those exhibited by Canadian deals. Decay is more rapid in white deal than in yellow, for the white deal absorbs more water than yellow deal. In the same way yellow deal absorbs more water and decays faster than red deal.

An example of the rapid decay of timber from dry-rot was given by Sir Thomas Deane in 1849 before the Institution of Civil Engineers in Ireland. It occurred in the Church of the Holy Trinity at Cork. On opening the floors under the pews, a most extraordinary appearance presented itself. There were flat fungi of immense size and thickness, some so large as almost to occupy a space equal to the size of a pew, and from one to three inches thick. In other places fungi appeared growing with the ordinary dry-rot, some of an unusual shape, in form like a convolvulus, with stems from a quarter to half an inch in diameter. When first exposed the whole was of a beautiful buff color, and emitted the usual smell of the dry-rot fungus.

During a part of the time occupied in the repairs of the church the weather was very rainy. The arches of the vaults having been turned before the roof was slated, the rain-water saturated the partly decayed oak beams. The flooring and joists, composed of fresh timber, were laid on the vaulting before it was dry, coming in contact at the same time with the old oak timber, which was abundantly supplied