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