The first or main ladder of the escape reaches about 24 feet high; and in the 1897 pattern the 40-feet ladders having one extension. Other escapes have extending-ladders rising to a height of 50 feet, and even 70 feet, these being in three lengths. But an Act of Parliament now provides that all buildings above a certain height must have means of exit attached; this generally takes the form of iron ladders or stairways outside the building. All parts of an escape are as far as possible interchangeable, and the ladder-vans are designed to carry any ladders in the brigade. And now the escape-drill is about to commence. The machine is placed against the building, which we must suppose to be burning. Up runs a fireman, with hands and feet on the rungs, to the window where the top of the ladder rests. If the window will not open readily, he may, in case of real need, smash it with his axe to obtain ready entrance. Then, if you watched him closely, you would see he did something which you would never think of doing. He fastens the end of his rope to the rung of his ladder, and, with the rest of the rope coiled over his arm, disappears into the room. The rope easily runs out as he moves, and affords him a means of speedily finding his way back to the window through the smoke; a very valuable arrangement it may prove to be, when the fireman finds an insensible person or a couple of children to rescue. One child he carries in his arm, and the other he throws across his shoulder, in the recognized brigade manner; and loaded thus, he gropes his way, guided by his one free hand, along the rope. Or there may be more than one adult to save. Then the rescued person is carried over the shoulder to the top of the trough, or shoot of netting, with which some escapes used to be fitted at the back of the escape-ladder, and is slipped down it feet first to the firemen waiting below; while the plucky fireman above returns for the next person in peril. The fireman will probably follow the last down the shoot by turning a somersault and coming down head first; meantime, holding the other's hands, and regulating the speed of the descent by pressing his knees and elbows against the sides of the netting. But without the shoot he descends by the ladder. Should the fire occur at a house surrounded by garden-wall, shrubs, or forecourt, the machine is wheeled as close as possible, and the extension or additional ladders can be placed at a somewhat different angle from the first, so as to bridge over the intervening space and reach the farthest window. The ladders of fire-escapes may also be useful substitutes for water-towers. A water-tower is a huge pipe, running up beside the ladder, or tower; and as three or four steamers play into the base of the huge pipe, the water is forced up it, and the jet at the top can then be directed anywhere into the burning building.