INK IMPREGNATED FABRIC RIBBONS AND CARBON COATED PAPER RIBBONS FOR AUTOMATIC COMPOSING MACHINES, TYPEWRITERS, AND LETTER WRITERS

POWER OPERATED TYPEWRITERS HAVING MEANS FOR PRODUCING A CONTROL TAPE, AND BEING ADAPTED FOR AUTOMATIC OPERATION UNDER CONTROL OF SUCH TAPE

Catalyst for use in the field of coal, petroleum, natural gas and oil sands