Technical notes. 744. Disclosures on: New syntheses of perfluorostyrene and other highly fluorinated derivatives, temperature-, radiation-, and vacuum-resistant magnetic tape, conductometrlc titration cell, mill work positioner, process for fabricating superconducting microbridges, apparatus for displaying average wind vane or other shaft position, document numbering machine responsive to staple in print area for printing in alternate area; editors, David Robbins and Alvin J. Englert.