CYCLOMETER (Gr. κύκλος, circle, and μέτρον, measure), an instrument used especially by cyclists to determine the distance they have traversed. In a common form a stud attached to one spoke of the wheel engages with a toothed pinion and moves it on one tooth at each revolution. The pinion is connected with a train of clockwork, the gearing of which bears such a ratio to the circumference of the wheel that the distance corresponding to the number of times it has revolved is shown on a dial in miles or other units.
CYCLONE (Gr. κυκλῶν, whirling, from κύκλος, a circle), an atmospheric system where the pressure is lowest at the centre. The winds in consequence tend to blow towards the centre, but being diverted according to Ferrel’s law they rotate spirally inwards at the surface of the earth in a direction contrary to the movement of the hands of a watch in the northern hemisphere, and the reverse in the southern hemisphere. The whole system has a motion of translation, being usually carried forward with the great wind-drifts like eddies upon a swift stream. Thus their direction of movement over the British Islands is usually from S.W. to N.E., though they may remain stationary or move in other directions. The strength of the winds depends upon the atmospheric gradients. (See [Meteorology].)
CYCLOPEAN MASONRY (from the Cyclopes, the supposed builders of the walls of Mycenae), a term in architecture, used, in conjunction with Pelasgic, to define the rude polygonal construction employed by the Greeks and the Etruscans in the walls of their cities. In the earliest examples they consist only of huge masses of rock, of irregular shape, piled one on the other and trusting to their great size and weight for cohesion; sometimes smaller pieces of rock filled up the interstices. The walls and gates of Tiryns and Mycenae were thus constructed. Later, these blocks were rudely shaped to fit one another. It is not always possible to decide the period by the type of construction, as this depended on the material; where stratified rocks could be obtained, horizontal coursing might be adopted; in fact, there are instances in Greece, where a later wall of cyclopean construction has been built over one with horizontal courses.
CYCLOPES (Κύκλωπες, the round-eyed, plural of Cyclops), a type of beings variously described in Greek mythology. In Homer they are gigantic cave-dwellers, cannibals having only one eye, living a pastoral life in the far west (Sicily), ignorant of law and order, fearing neither gods nor men. The most prominent among them was Polyphemus. In Hesiod (Theogony, 264) they are the three sons of Uranus and Gaea—Brontes, Steropes and Arges,—storm-gods belonging to the family of the Titans, who furnished Zeus with thunder and lightning out of gratitude for his having released them from Tartarus. They were slain by Apollo for having forged the thunderbolt with which Zeus slew Asclepius. Later legend transferred their abode to Mt Aetna, the Lipari islands or Lemnos, where they assisted Hephaestus at his forge. A third class of Cyclopes are the builders of the so-called “Cyclopean” walls of Mycenae and Tiryns, giants with arms in their belly, who were said to have been brought by Proetus from Lycia to Argos, his original home (Pausanias ii. 16. 5; 25. 8). Like the Curetes and Telchines they are mythical types of prehistoric workmen and architects, and as such the objects of worship.
The standard work on these and similar mythological characters is M. Mayer, Die Giganten und Titanen (1887); see also A. Boltz, Die Kyklopen (1885), who endeavours to show that they were an historical people; W. Mannhardt, Wald- und Feldkulte (1904); J. E. Harrison, Myths of the Odyssey (1882); and article in Roscher’s Lexikon der Mythologie (bibliography).