LACTONES OF THE DIAZAXANTHENE SERIES, THEIR PRODUCTION AND THEIR USE AS DYE-FORMING COMPONENTS FOR COPYING METHODS

摘要

The movement of a section of a ship during assembly or repair is facilitated by cushions of pressurised fluid positioned beneath the section, lateral escape of the fluid being prevented by flexible skirts. When in position the section is raised to a desired height by fluid inflatable lift bags. The fluid may be water, and when working in a dry dock is advantageously sea water.