A machine in which the descent of a weight is made to turn a spit. The ordinary construction is represented in the annexed sketch, which may be briefly described as follows: - a is a barrel, round which is coiled a line of considerable length; the other end of this line is reeved through two threefold or fourfold pulleys, a b and c, generally placed against the outside of the house, and at a considerable height, so as to allow the greater range for the weight d attached to the lower block c to act in. Upon the spindle of the barrel is fixed a pulley e, and a similar one is also fitted to the spit g, and round these two pulleys passes an endless chain. The weight d being sufficient to overcome the friction of the machine, descends slowly, and uncoils the line by turning the barrel round, which causes the spit likewise to revolve. To render the motion equal, and to prevent the jerks which would arise in the case of the meat being unequally spitted, so as to act with more force on one side of the spit than on the other, a wheel of about forty teeth is placed on the axis of the barrel, and works into a double threaded screw, placed upon the spindle of the horizontal fly, which thus performs a revolution for every two teeth of the wheel, or twenty revolutions for one of the barrel a, and by this great velocity prevents any alteration in the motion of the barrel.
When the weight has descended through its range, it is wound up by a handle which can be fixed on a square end of the barrel spindle. The Chinese crane would, perhaps, be found a superior arrangement to the treble or fourfold blocks, as the friction is considerably less.