the torch or to prevent them from doing so. These cocks are often used for
regulating the pressure and amount of gas flowing to the welding head, but
are not always constructed for this purpose and should not be so used when
it is possible to secure pressure adjustment at the regulators (Figure 16).

Figure 16 shows three different sizes of torches. The number 5 torch is
designed especially for jewelers' work and thin sheet steel welding. It is
eleven inches in length and weighs nineteen ounces. The tips for the number
10 torch are interchangeable with the number 5. The number 10 torch is
adapted for general use on light and medium heavy work. It has six tips and
its length is sixteen inches, with a weight of twenty-three ounces.

The number 15 torch is designed for heavy work, being twenty-five inches in
length, permitting the operator to stand away from the heat of the metal
being worked. These heavy tips are in two parts, the oxygen check being
renewable.

[Illustration: Figure 16.--Three Sizes of Torches, with Tips]

Figures 17 and 18 show two sizes of another welding torch. Still another
type is shown in Figure 19 with four interchangeable tips, the function of
each being as follows:

No. 1. For heavy castings.
No. 2. Light castings and heavy sheet metal.
No. 3. Light sheet metal.
No. 4. Very light sheet metal and wire.

[Illustration: Figure 17.--Cox Welding Torch (No. 1)]