ltered. the tubes, have been used for years, but they cannot The annexed engraving represents a head or clamp be employed unless the boiler is quite cold, otherwise for house brooms; it is made of malleable iron in BIRD'S GEARED DIFFERENTIAL PULLEY. they will be destroyed. Steel-wire brushes have… … The engraving published herewit 1 shows an im- end. By inserting it, when the clamp is closed, proved brush made of steel wire, spring tempered. through the yoke into the socket, and turning it It can be used when the boiler is hot, which is a de- round, the screw in the socket cuts a thread on the…
