Abstract: A device measures cylindricity of a cylinder having an axial end, a circumference and an inside diameter. The device includes a track for placement at an axial end of the cylinder to be measured. The track extends around the circumference of the cylinder. A pair of trucks are mounded to the track for movement around the cylinder circumference. A sighting beam generator, in particular, a laser, is connected to each truck for aiming sighting beams axially along the inside diameter of the cylinder. A micrometer adjustment is connected between each laser and its truck for adjusting a radial position of each sighting beam.

Abstract: A novel liquid crystal compound has the molecular structure: ##STR1## where R is an alkyl group, which may contain up to 18 carbon atoms and which may be normal or branched and may contain a chiral center, ##STR2## is a bicyclo (2.2.2) octane ring, ##STR3## is a phenyl ring and CN is a cyano group, n being an integer greater than 0 preferably 1 or 2.The compound may be used in mixtures with other liquid crystal compounds in the same or other families and the compound or mixtures may be used in known liquid crystal devices, eg the twisted nematic and cholesteric-to-nematic phase change devices, depending on its properties.