In the double-lift machine there are double the number of hooks that there would be in a single-lift machine of the same size, but the same number of needles; each needle is connected with two hooks, as shown in Fig. 32, which gives one row of hooks and needles for an 8-row or 400 machine. There are two griffes, one working above the other, as shown at A and B, Fig. 33. E, E is the top griffe in both; C, C is the bottom griffe, shown complete at A, but at B the side-bar of the frame is omitted, leaving only the knives to show how they fall in between those of the bottom griffe; D, D^1 are the two slide rods or spindles which keep the griffes steady in their traverse. There must be a sufficient space between the frame C of the lower griffe and that of the upper griffe, E, to allow of the required draw being given to form the sheds without them coming into contact. In these machines, although there are 16 hooks in the row, they only act as eight, so far as forming the pattern is concerned, as two hooks are governed by one needle; the additional hooks are solely for the purpose of obtaining a rising and falling shed. Each pair of hooks is connected together at the bottom by a piece of strong cotton cord, called the tail cord or tug cord, as shown in Fig. 35. The griffes are raised by two levers arranged side by side, and similar to the one shown in Fig. 17. These levers are wrought by rods connecting them to a double crank, or sometimes to a tappet, on the tappet shaft of the loom. The common form of crank is shown at A, Fig. 34. B is the tappet shaft, and on the end of it is fastened a disc. A second disc, which carries the double crank, G, is bolted against this one, and can be shifted to whatever position is required to give the tread at the correct time. The cylinder is driven from an eccentric on the crank-shaft as before described. One of the griffes rises for each shot, the other falling at the same time; but the cylinder must come in for every shot, and it is here that the principal fault in this machine lies. Not only has the cylinder to travel at a high speed, but when one griffe is at its highest position, it has to press against the needles, so as to clear away those hooks that are not to be lifted by the lower griffe, which should now be beginning to rise; and in consequence of the needles being attached to two hooks, one belonging to the upper griffe, and the other to the lower one, it follows that those needles that are pressed in by the cards have to spring back the hooks connected with them that are raised by the upper griffe, which is a severe strain on both needles and cards. To prevent the hooks being pushed off the upper griffe, they must have larger turns on them than would otherwise be necessary.