In the crude rubber received at the factory are sticks, dirt, bits of leaves, and beetles. These are removed by grinding the rubber in a water bath. The particles of dirt are thus washed away. The rubber is now pure enough for the first process of manufacture. The next step is to mix the rubber with the chemicals. This is called compounding. In the factory here shown four or five hundred different chemicals are used to compound with rubber. Some of these are to give strength and toughness, others to give color to the rubber. It is possible to make rubber that is tougher than steel. The rubber is now ready for manufacturing purposes. What next happens to it depends on the uses to which it is to be put. For example, if it is to be made into the bandages that dentists stretch across the mouths of patients, it must be rolled very thin. This process is called sheeting. One of the greatest uses for rubber today is in the manufacture of automobile tires. You see here an automobile tire being built up. The framework of a tire is its body of fabric or tough cloth. On an iron core, the shape of the tire, this fabric is first wound several thicknesses. This is what the men here are doing. It is a work that demands care and skill. To become an expert workman in this department a man must have a steady hand, deft fingers, a clear eye, and good judgement. There is another way of building up tires. This is by using two crossed layers of heavy cords instead of fabric to wrap about the iron core. These cords have been filled with a rubber solution under high pressure. They are laid on the core by a machine. A tire so built up is called a Silvertown. Keystone ID: 22058 Note: All titles, descriptions, and location coordinates are from the original Keystone Slide documentation as supplied by the Keystone View Company. No text has been edited or changed.