The smooth steel surface of the bent mainspring _c_ prevents the vise
jaws from marking the soft steel of the regulator bar. A person who has
not tried this method of cutting out soft steel would not believe with
what facility pieces can be shaped. Any workman who has a universal face
plate to his lathe can turn out the center of the regulator bar to
receive the disk _C_, and also turn out the center of the regulator
spring _B_. What we have said about the regulator bar applies also to
the regulator spring _B_. This spring is attached to the cock _D_ by
means of two small screws at _n_.

The micrometer screw _F_ is tapped through _B''_ as in the ordinary
Howard regulator, and the screw should be about No. 6 of a Swiss
screw-plate. The wire from which such screw is made should be 1/10" in
diameter. The steel cap _C_ is fitted like the finer forms of Swiss
watches. The hairspring stud _E_ is of steel, shaped as shown, and comes
outlined with the other parts.


TO TEMPER AND POLISH STEEL.

The regulator bar should be hardened by being placed in a folded piece
of sheet iron and heated red hot, and thrown into cold water. The
regulator bar _A A'_ is about 3" long; and for holding it for
hardening, cut a piece of thin sheet iron 2½" by 3¼" and fold it
through the middle lengthwise, as indicated by the dotted line _g_, Fig.
44. The sheet iron when folded will appear as shown at Fig. 45. A piece
of flat sheet metal of the same thickness as the regulator bar should be
placed between the iron leaves _I I_, and the leaves beaten down with a
hammer, that the iron may serve as a support for the regulator during