Screen
See SAND-SCREEN.
Screw-jack, or jack-screw, is a lifting-machine in which the power consists of a strong screw, which is made to rotate by means of a large nut which rests upon a base or pedestal. It is raised or lowered by turning the nut.
Twelve hundred entries from the golden age of cast metal — how bells are founded, why brass is not bronze, what a cupola melts and a core withstands — by Simpson Bolland, the trade's great teacher.
See SAND-SCREEN.
Screw-jack, or jack-screw, is a lifting-machine in which the power consists of a strong screw, which is made to rotate by means of a large nut which rests upon a base or pedestal. It is raised or lowered by turning the nut.