In many cases, on the contrary, the subtle fluid has pulverized a hard stone on the spot and reduced it to powder. Tiles and slates are very often torn off the roofs: the lightning makes them fly through the air. Sometimes it is content to perforate them with a multitude of little holes. As for chimneys, they are generally very ill-treated by the meteor. The blows of which they are victims are to be accounted for easily, for they offer perfect powers of conducting to the fulminant matter, firstly, because of their prominence on the summit of the building, especially when they are surmounted by a vane. Again, the flue is often in cast-iron, and if it is bricked it is supported by bars of iron. The surface of the interior is covered with a layer of soot, an excellent conductor, and a stove-pipe often opens into it. Then, too, the hearth and its surroundings are more or less made of metal. Finally, the column of smoke and of hot, damp air rising into the air, shows the lightning the way. The latter often accepts this invitation, and very frequently gets into a house by the chimney, where everything seems ready for its reception. Rafters and doors are sometimes bored through with one or two holes by the spark, and split or furrowed more or less deeply. A curious fact is that it is rare to find the slightest trace of combustion round them. In the month of August, 1887, lightning struck the belfry of the church at Abrest (Allier), carrying off part of the roof. It destroyed the walls of the porch, and in both sides of the swing doors bored two holes, each as big as a pigeon's egg, and as symmetrically as if they had been made by the hand of man. The cleavage of beams is amongst the most extraordinary injuries to be observed on woodwork. Lightning works with wrought wood just as it does when the tree is in full sap: it reduces it to rags, and follows the direction of the fibres. With what crimes lightning is charged! When it is a question of robbing a house, it spares nothing in its way. The window-panes fly in pieces, and sometimes are thrown a long way off. Often they are melted and disappear totally. In July, 1783, at Campo Sampiero Castello (Padua), lightning struck a building full of hay; the windows had glass in them, and the panes were melted _without the hay catching fire_! A still more astonishing phenomenon is that of the total disappearance of the glass panes, observed at the Castle of Upsal, on August 24, 1760. Lightning visited this edifice and then took flight, carrying off sixteen panes out of a window. Not the smallest fragment of them was ever found. Perhaps, as often happens, terrific heat was generated, and the glass evaporated.