Some years since we had a great deal to do with “Fire Surveys;” that is to say, surveying buildings to estimate the cost of reinstating them after being destroyed by fire; and we often noticed that the wood bond, being rotten, was seriously charred by the fire, and had to be cut out in short lengths, and brickwork in cement “pinned in” in its place. Brestsummers and story posts are rarely sufficiently burnt to affect the stability of the front wall of a shop building. In bad foundations, it used to be common, before concrete came into vogue, to lie planks to build upon. Unless these planks were absolutely wet, they were certain to rot in such situations, and the walls settled; and most likely irregularly, rending the building to pieces. Instances of such kind of failure frequently occur. It was found necessary, a few years since, to underpin three of the large houses in Grosvenor Place, London, at an immense expense. In one of these houses the floors were not less than three inches out of level, the planking had been seven inches thick, and most of it was completely rotten: it was of yellow fir. A like accident happened to Norfolk House, St. James’s Square, London, where oak planking had been used. As an example of the danger of trusting to timber in supporting heavy stone or brickwork, the failure of the curb of the brick dome of the church of St. Mark, at Venice, may be cited. This dome was built upon a curb of larch timber, put together in thicknesses, with the joints crossed, and was intended to resist the tendency which a dome has to spread outwards at the base. In 1729, a large crack and several smaller ones were observed in the dome. On examination, the wooden curb was found to be in a completely rotten state, and it was necessary to raise a scaffold from the bottom to secure the dome from ruin. After it was secured from falling, the wooden curb was removed, and a course of stone, with a strong band of iron, was put in its place. It is said that another and very important source of destruction is the applying end to end of two different kinds of wood: oak to fir, oak to teak or lignum vitæ; the harder of the two will decay at the point of juncture. The bad effects resulting from damp walls are still further increased by hasty finishing. To enclose with plastering and joiners’ work the walls and timbers of a building while they are in a damp state is the most certain means of causing the building to fall into a premature state of decay. Mr. George Baker, builder of the National Gallery, London, remarked, in 1835, “I have seen the dry rot all over Baltic timber in three years, in consequence of putting it in contact with moist brickwork; the rot was caused by the badness of the mortar, it was so long drying.”