The two great desiderata in the stage of the lock that we are now considering were security and rapidity, both of which must have forced themselves on the notice of the primeval householder each time he crossed the threshold of his door. I shall begin with branch A in which security only appears to have been aimed at, and then proceed to those in which security and rapidity were combined. The first idea which suggested itself was to put a bolt in a box, so that no one could get at it to lift the tumbler without a key especially adapted to enter the box and raise it, but as long as only one tumbler was used it must have been very easy to pick such a lock by raising the tumbler with any sharp-pointed instrument that might be introduced into the hole. By using two tumblers, it would be impossible to raise them both at once, except by a key constructed with projections or teeth to fit into notches or holes in the tumblers, which teeth must necessarily be at the same distance apart as the notches, and as the tumblers were hidden in the box, no one unacquainted with the contrivance could make a key to fit the lock, which by this means afforded to some extent the security that was requisite. Scandinavia appears to have been the headquarters of this class of locks, or at any rate the part of the world in which they have chiefly survived at the present time; one of the simplest of which is represented in figs. 9A, 10A, and 11A, Plate I., from the Faroe Islands. _e_ is the wooden block into which is cut a horizontal groove for the bolt _a_, and two vertical grooves in which the pins or tumblers, _d d_, play, and when the bolt is shut to, they fall of their own accord into the holes _f f_. The key, _c_, is passed horizontally into another groove cut for it in the block, above and parallel to the one for the bolt. Two notches are cut in the tumblers to enable the key to pass, and when pressed in horizontally as far as it will go, the teeth of the key, _b b_, coincide exactly with the notches in the tumblers, so that when the key is afterwards raised vertically, it raises the tumblers, by means of the notches, out of the holes, _f f_, on the upper surface of the bolt, and the bolt can then be drawn out by the hand. It will be seen that this lock requires as many motions as the bolt (figs. 6, 7, and 8, Plate I.). It requires only one motion to shut it, when the two tumblers fall into the holes and keep it fast, but to open it, it is necessary to use both hands, one to raise the key and the other to draw out the bolt. It may therefore be termed for distinction a hand-drawn lock. No time is saved by this process, but the lock, for such we must now begin to call it rather than bolt, is rendered more secure. Different kinds of these locks, but all on the same principle, are in use in out of the way parts of Scotland. Figs. 12A to 17A, Plate I., similar to the last but having a slight difference in the shape of the notches, is a