In order to obtain an idea of the explosive effectiveness of roburite, eight ounces of the explosive were placed on a plate of the very best steel, at the point marked A in Fig. 1, which shows the state of the plate after the explosion. This plate was 3 ft. square by ½ in. thick, and a bulge of about 1 ft. diam. and 3½ in. deep was caused by the explosion. Twelve ounces of the explosive were then placed at A (Fig. 2) on a cast iron plate, 6 in. thick, and weighing nearly three tons. After the explosion the plate was found to be broken transversely, in the manner shown in the engraving. Unlike dynamite, roburite is said to be in no way affected by varying temperatures, and if duly protected against damp, it may be kept for years in any climate, without its efficiency becoming in any way impaired. It is also claimed by the manufacturers that roburite has an explosive force greater than dynamite by at least 25 per cent.
In exploding, roburite does not produce noxious gases, and, therefore, may be used without intermission, while the poisonous gases given off by dynamite often necessitate the stoppage of work, in some cases for a considerable time. This new explosive is applicable for use in mines and quarries, and for torpedoes and blasting operations generally.—_Industries_.
Speaking of the large apartment house in New York lately condemned for dry rot (see illustration last November number of this paper), the _American Architect_ says: A few of the floors were of spruce, and these, as might be expected, had resisted the rot much better than the hemlock, and were still sound, but the construction ought certainly to be changed. In view of the dangers from this source which attend efforts to provide fire‐resisting floors of wood, it would seem that something might be done with light shapes of rolled iron beams. We have seen rolled floor beams used in Paris nearly as light as wooden ones of the same depth, and a tier of these, deafened with mortar on wire in the French manner, and wire‐lathed underneath, with a wooden floor over, would cost little more than a solid mass of wooden beams, and would be proof against rot as well as fire.
BATHING ESTABLISHMENT AND CASINO IN VITTEL (VOSGES). BUILT BY CHARLES GARNIER, ARCHITECT, OF PARIS.