n from the roof was
collected in gutters round the compluvium, and discharged from thence
into a tank or open basin in the floor called the impluvium. (2) In the
_tetrastylon_ additional support was required in consequence of the
dimensions of the hall; this was given by columns placed at the four
angles of the impluvium. (3) _Corinthian_ is the term given to the
species where additional columns were required. (4) In the
_displuviatum_ the roofs, instead of sloping down towards the
compluvium, sloped outwards, the gutters being on the outer walls; there
was still an opening in the roof, and an impluvium to catch the rain
falling through. This species of roof, Vitruvius states, is constantly
in want of repair, as the water does not easily run away, owing to the
stoppage in the rain-water pipes. (5) The _testudinatum_ was employed
when the hall was small and another floor was built over it; no example
of this type has been found at Pompeii, and only one of the cavaedium
displuviatum.

CAVAGNARI, SIR PIERRE LOUIS NAPOLEON (1841-1879), British military
administrator, the son of a French general by his marriage with an Irish
lady, was born at Stenay, in the department of the Meuse, on the 4th of
July 1841. He nevertheless obtained naturalization as an Englishman, and
entered the military service of the East India Company. After passing
through the college at Addiscombe, he served through the Oudh campaign
against the mutineers in 1858 and 1859. In 1861 he was appointed an
assistant commissioner in the Punjab, and in 1877 became deputy
commissioner of Peshawar and took part in several expeditions against
the hill tribes. In 1878 he was attached to the staff of the British
mission to Kabul, which the Afghans refused to allow to proceed. In May
1879, after the death of the amir Shere Ali, Cavagnari negotiated and
signed the treaty of Gandamak with his successor, Yakub Khan. By this
the Afghans agreed to admit a British resident at Kabul, and the post
was conferred on Cavagnari, who also received the Star of India and was
made a K.C.B. He took up his residence in July, and for a time all
seemed to go well, but on the 3rd of September Cavagnari and the other
European members of the mission were massacred in a sudden rising of
mutinous Afghan troops. (See AFGHANISTAN.)

CAVAIGNAC, JEAN BAPTISTE (1762-1829), French politician, was born at
Gourdon (Lot). He was sent by his department as deputy to the
Convention, where