CALLOT

callot, jacques (1592-1635), french engraver, was born at nancy in lorraine, where his father, jean callot, was a herald-at-arms. he early discovered a very strong predilection for art, and at the age of twelve quitted home without his father's consent, and set out for rome where he intended to prosecute his studies. being utterly destitute of funds he joined a troop of bohemians, and arrived in their company at florence. in this city he had the good fortune to attract the notice of a gentleman of the court, who supplied him with the means of study; but he removed in a short time to rome, where, however, he was recognized by some relatives, who immediately compelled him to return home. two years after this, and when only fourteen years old, he again left france contrary to the wishes of his friends, and reached turin before he was overtaken by his elder brother, who had been despatched in quest of him. as his enthusiasm for art remained undiminished after these disappointments, he was at last allowed to accompany the duke of lorraine's envoy to the papal court. his first care was to study the art of design, of which in a short time he became a perfect master. philip thomasin instructed him in the use of the graver, which, however, he ultimately abandoned, substituting the point as better adapted for his purposes. from rome he went to florence, where he remained till the death of cosimo ii., the maecenas of these times. on returning to his native country he was warmly received by the then duke of lorraine, who admired and encouraged him. as his fame was now spread abroad in various countries of europe, many distinguished persons gave him commissions to execute. by the infanta isabella, sovereign of the low countries, he was commissioned to engrave a design of the siege of breda; and at the request of louis xiii. he designed the siege of rochelle and the attack on the isle of re. when, however, in 1631 he was desired by that monarch to execute an engraving of the siege of nancy, which he had just taken, callot refused, saying, "i would rather cut off my thumb than do anything against the honour of my prince and of my country"; to which louis replied that the duke of lorraine was happy in possessing such subjects as callot. shortly after this he returned to his native place, from which the king failed to allure him with the offer of a handsome pension. he engraved in all about 1600 pieces, the best of which are those executed in aquafortis. no one ever possessed in a higher degree the talent for grouping a large number of figures in a small space, and of representing with two or three bold strokes the expression, action and peculiar features of each individual. freedom, variety and _naivete_ characterize all his pieces. his fairs, his miseries of war, his sieges, his temptation of st anthony and his conversion of st paul are the best-known of his plates. see also edouard meaume, _recherches sur la vie de jacques callot_ (1860). callovian (from _callovium_, the latinized form of kellaways, a village not far from chippenham in wiltshire), in geology, the name introduced by d'orbigny for the strata which constitute the base of the oxfordian or lowermost stage of the middle oolites. the term used by d'orbigny in 1844 was "kellovien," subsequently altered to "callovien" in 1849; william smith wrote "kellaways" or "kelloways stone" towards the close of the 18th century. in england it is now usual to speak of the kellaways beds; these comprise (1) the kellaways rock, alternating clays and sands with frequent but irregular concretionary calcareous sandstones, with abundant fossils; and (2) a lower division, the kellaways clay, which often contains much selenite but is poor in fossils. the lithological characters are impersistent, and the sandy phase encroaches sometimes more, sometimes less, upon the true oxford clay. the rocks may be traced from wiltshire into bedfordshire, lincolnshire and yorkshire, where they are well exposed in the cliffs at scarborough and gristhorpe, at hackness (90 ft.), newtondale (80 ft.) and kepwick (100 ft.). in yorkshire, however, the callovian rocks lie upon a somewhat higher palaeontological horizon than in wiltshire. in england, _kepplerites calloviensis_ is taken as the zone fossil; other common forms are _cosmoceras modiolare_, _c. gowerianum_, _belemnites oweni_, _ancyloceras calloviense_, _nautilus calloviensis_, _avicula ovalis_, _gryphaea bilobata_, &c. on the european continent the "callovien" stage is used in a sense that is not exactly synonymous with the english callovian; it is employed to embrace beds that lie both higher and lower in the time-scale. thus, the continental callovien includes the following zones:-- upper callovien / zone of _peltoceras athleta_, _cosmoceras duncani_, (divesien) \ _quenstedtoceras lamberti_ and _q. mariae._ / zone of _reineckia anceps_, _stephanoceras lower callovien < coronatum_ and _cosmoceras jason_ and a lower zone | of _c. gowerianum_ and _macrocephalites \ macrocephalus_. rocks of callovian age (according to the continental classification) are widely spread in europe, which, with the exception of numerous insular masses, was covered by the callovian sea. the largest of these land areas lay over scandinavia and finland, and extended eastward as far as the 40th meridian. in arctic regions these rocks have been discovered in spitzbergen, franz josef land, the east coast of greenland, and siberia. they occur in the hebrides and skye and in england as indicated above. in france they are well exposed on the coast of calvados between trouville and dives, where the marls and clays are 200 ft. thick. in the ardennes clays bearing pyrites and oolitic limonite are about 30 ft. thick. around poitiers the callovian is 100 ft. thick, but the formation thins in the direction of the jura. clays and shales with ferruginous oolites represent the callovian of germany; while in russia the deposits of this age are mainly argillaceous. in north america callovian fossils are found in california; in south america in bolivia. in africa they have been found in algeria and morocco, in somaliland and zanzibar, and on the west coast of madagascar. in india they are represented by the shales and limestones of the chari series of cutch. callovian rocks are also recorded from new guinea and the moluccas. see jurassic; also a. de lapparent, _traite de geologie_, vol. ii. (5th ed., 1906), and h.b. woodward, "the jurassic rocks of britain," _mem. geol. survey_, vol. v. (j. a. h.)