dish. If the operation is continued the metal will become hemispherical in form. The metal used should be soft steel from 1/16 to 3/16 in. thick.
Fig. 99. Cast-iron Block Used in Making Raised Forms
Fig. 99 shows a block of cast iron which has a hole through it countersunk at the top. This may be used to raise the form on. The method of raising a form is to heat the sheet and hammer it over the hole in the iron block, starting by hammering around the edge with a series of blows until
Fig. 100. Hammer Used in Raising