Another invention from Brooklyn is of far greater importance than the one just recorded, for it is of a life-saving character, and is designed to prevent those collisions at sea which seem to be so greatly on the increase. It consists of a marine brake, and is the contrivance of Mr John M‘Adams. The experimental vessel, _The Florence_, which is fitted with the brake, has been reported upon officially, and the behaviour of the apparatus is highly commended. The brake consists of two wings made of steel, one on each side of the vessel and below water-level. These have the appearance of flat boards about eight feet square, hinged to the stern-post, and which when not in action fold forwards, secured by hidden chains, close to and touching the vessel’s sides. In case of danger of collision, the touch of a button by the captain on the bridge will loosen these chains, and cause some springs to act upon the wings, so that they fly out at right angles to the sides of the ship. In this position they are held by the now lengthened chains, and form an obstacle to the water, which checks the motion of the vessel immediately, even if the engines continue to work. If the engines are stopped at the moment the brake is put into action, the ship is brought to a standstill in twenty-two seconds. If, again, the engine be stopped and reversed at the moment of working the brake, the vessel commences to go astern in the remarkably short space of twelve seconds. It will be seen from these results that the invention gives every promise of being of great use. Besides being efficient, it is simple in character, and, from its nature, cannot be a very expensive additional fitting to a ship. The lamentable accident at the Crarae Quarries, by which seven persons lost their lives, is happily a most unusual one, although in character it is closely allied with those fatalities from ‘choke-damp’ by which so many poor colliers have been killed. The explosion of gas underground, or of gunpowder above ground, leads to the evolution of a quantity of carbonic acid gas, or, to call it by its proper name, carbon dioxide, the principal product of combustion in either case. In the workings of a mine, this gas fills every available space, and has no outlet. In the quarry, on the occasion referred to, much the same condition of affairs existed, for there was no wind to carry off the deadly vapour, and its natural heaviness made it cling to the place of its creation. The surviving relatives of the victims of this accident have our heartfelt sympathy. They will be comforted by knowing that death under such conditions is supposed to be painless. It is a sending to sleep, but a sleep, unfortunately, from which there is no awakening in this world.