I assume you're wanting to spit-roast a lamb. In this case, choose a young, lean lamb, well matured and weighing no more than 10kg. With a cleaver or sharp axe and working from the inside, chop partially through the spine in the area of the ribs. Open and flatten this section, remove and discard the two top chops on either side to allow the heat to penetrate the shoulders, then trim away all extraneous fat and loose skin. Push the pointed end of the long rod through the flesh from tail to neck, between backbone and skin. Attach the hind legs to the cross bar with wire. Wire also the pieces of flesh between tail and feet to the cross bar to hold open the leg meat. Slash the leg flesh through to the bone on the inner side so the meat cooks evenly. To hold the carcass open, you'll need three green twigs sticks with pointed ends, similar in length to the cross bar. Place these across the flank, shoulders and forelegs. Pierce the ends through the flesh to hold it open. To suspend the lamb over the coals, force the spit well into the ground, just off the vertical, with the lamb's belly towards the heat. At the start pile the coals mainly under the legs, which take longer to cook. After 30 minutes or so rake the coals evenly under the lamb. To turn the lamb, pull the rod out of the ground, revolve it and present the opposite side to the heat. The total cooking time will be about three hours, when the internal temperature of the leg meat registers 65 to 70 degrees centigrade on a meat thermometer, or juices run faintly tinged with pink when the flesh is pierced.