BRICKS. 1 . Simple screw machines. 2. Screw machines with distributing cyhnders. 3. Screw machines with rollers and distributing cylinders. I. Simple Screw Machines.^ — These are not desirable, as they can only treat pure clays or those having already undergone preliminary working. Moreover, they… … Eig. 112. — Simple Screw Machine (Jager). as, having no feeding cylinders, the clay is not drawn up by the screws ; therefore their use is not recommended. 2. Screw Machines with one or two Distributing Cylinders. — To make sure of regular distribution and con- tinuous flow of clay to the pug-mill,…