22, 331. Bastian, C. O. Oct. 3. Filaments. - A tungsten, molybdenum, or other filament or wire for a lamp &c., is coated, before or after being formed into a closed helix, with a material which is removed or decomposed after the filament has been mounted on its final support, so that the turns of the filament become separated. The coating- material may be an oxide of the filament metal or another metal such as calcium, an electrolytically-deposited metal such as copper, or cotton, varnish, or collodion. To facilitate attachment to leading-in wires or supports, the ends of the filaments may be left uncoiled. Removal or decomposition of the coating may precede or follow the mounting of the filament in the bulb, and may be effected by dissociation, electrolytic or chemical action, or volatilization in a vacuum or inert gas. Oxide may be dissociated by heating during exhaustion of the lamp. It is stated that the finished filament has a clean polished surface. The bulb may contain inert gases. Specifications 8144/12, [Class 37, Electricity, Measuring &c.], 21, 029/13, and 22, 024/13 are referred to. According to the Provisional Specification, the invention is applicable to filaments of zigzag or other closely-arranged form; also the filaments may be ' set ' otherwise than by heating