629,518. Levels. SVENSKA ACKUMULATOR AKTIEBOLAGET JUNGNER. Nov. 11, 1947, No. 30030. Convention date, Nov. 13, 1946. Drawings to Specification. [Class 97 (ii)] A liquid level is provided with a cylindrical lens, the bubble of the level being located on or in the proximity of the focal line of the lens so that at least one of the rounded ends of the bubble appears as a straight line. The cylindrical lens may be formed as a portion of the liquid-containing tube or may be provided as a separate lens, and may be combined with a prism system of known type wherein the images of the two ends of the bubble are positioned together along a central line.