Communicales, Chr. Communion vessels, made especially to be carried in procession in Rome.
Compass. In Music, the whole range of sounds capable of being produced by a voice or instrument.
Compass-headed, Arch. A semicircular arch.
Compass Roof, Arch. An open timber roof.
Compass Window, Arch. A bay-window on a circular plan.
Compes. (1) A ring of gold or silver worn by the Romans round the leg, just above the ankle. (2) The chains or shackles worn round the ankle by slaves or prisoners.
Compitalia, Compitales. A festival held by the Romans in honour of the Lares compitales, celebrated in the cross-roads, compitia, where the images of those deities were often placed in niches.
Complement, Her. Applied to the moon, when full.
Complement. In Music, the interval to be added to another interval to make an octave; e.g. a third to a sixth; a fourth to a fifth, &c.
Complementary Colours. If the whole of the light which is absorbed by a coloured body were reunited with the whole of the light which it reflects, white light would result; in this case the absorbed colours are complementary to those which are reflected. The colour given by a mixture of the colours of any portion of a spectrum is the complement of the remaining portion. Red is complementary to Green, Orange to Blue, Greenish-Yellow to Violet, Indigo to Orange Yellow, and, in each case, vice versâ.