Encyclopaedia Britannica > Volume 15, PLA-RAM

PON
I»or typool,„oplc ; in which abjeft ilavcry Trebifond and all Pontus
Ponza. continued ever iince. ,
PONTYPOOL, a town of Monmouthlhire in Png-
land, feated between two hills. It is but a (mail place,^
though noted for its iron-mills, great manufaaure of
japanned mugs, &c. W. Long. 3. 6. N.Lat. 51. 42.
PONZA, or Pontia, is a final! ifland of the 1 uican
Sea, well known to be the place to which many illufln-
ous Romans were fornaerly banilhed. It is fituated on
the coaft of Italy near Terracina, and in the neighbour¬
hood of other fmall iflands or rocks named Patmarole,
Zannone, &c. between the ifland of Ventouenne and
Monte Circello. All thefe iflands were viflted by Sir
William Hamilton in the year 1785 ; and an account of
his journey is given in a letter to Sir J. Banks, which
appeared in the Phil. Tranf. vol. lx*vi. p. 365. Sir
William arrived at Ponza on the 2oth Auguft ; and,
according to his account, it lies about 30 miles from
Ventotienne. On the 21ft he went round it in a boat.
Its length is about live miles, but its breadth is nowhere
above half a mile, and in fome places not more than 500
feet. It is furrounded by a multitude of detached rocks,
fome of them very high, and moll of them compofed
of a compaa lava. There are many irregularly formed
bafaltes, but none in large columns. In fume piace$
they have a reddifh tinge from iron ochie, are veiy
fmall, and irregularly laid over one another. Some
Hand perpendicularly, others obliquely, and fome lie
horizontally. 'flic' rocks themfelves in which thefe
mafles are found are lava of the fame nature w ith the
bafaltes. At firft fight they appear like the rums of
ancient Roman brick or tyle buildings. One rock is
compofed of large fpherical baialts, and in other places
our author found the lava inclined to take the like
fpherical form, though on a much fmaller fcale, feme of
the former bafalts being near two feet in diameter. All
thefe rocks, in our author's opinion, have been detached
by the fea from this ifland, which is entirely compofed
of volcanic matter, lavas, and tufas ol various qualities
and colours, as green, yellow, black, and white. Some
of thefe matters are more compact in their teKtiu e than
others ; and in fome parts great tracts feem to have un¬
dergone fimilar operations, which ilill fubfift at^ a fpot
called the Pifaarelli, on the outfide of the Solxatava,
near Puzzole, and where a hot fulphureous vitriolic
acid vapour converts all which it penetrates, whether
lavas, tufas, volcanic aflies, or putnice-ftones, into a pure
clay, mollly white, or with a tint of red, blue, green,
or yellow. , . r
In one part of this ifland there is a fort of tufa re¬
markably good for the purpofe of building. It is as
bard as Bath-ftone, and nearly of the fame colour, with-
out any mixture of lava or pumice-done, vs Inch iifually
abound in the tufas of Naples, Baia, and Puzzoli.
The ifland of Palmarole which is about four miles
from Ponza, is not much more than a mile in circum¬
ference. It is compofed of the fame volcanic matter,
and probably was once a part of Ponza; and in our
author’s opinion it looks as if the ifland of Zannone,
which lies about the fame diftance from Ponza, was once
likewife a part of the fame ; for many rocks of lava
rife above water in a line betwixt the two laft-mentioned
Hands, and the water there is much more ihallow than
ia the gulf of Terracina.
Zannone is much larger and higher than Palmarole;
37* 1 poo
and that half of it next the continent is conrif fed oi a
lime Hone fimilar to that of the Apennines near it; the
other half is compofed of lavas and tutas, vefembhng in __
every other refpedt the foil of the iflands juft deferibed.
Neither Palmarok nor Zannone are inhabited ; but the_
latter furnifhes abundance of brufhwood for the ufe ot
the inhabitants of Ponza, whole number, including the
garrifon, amounts to near 1700. 1 he uninhaoited
ifland of St Stefano in like manner furniikes wood for •
the people of Ventotienne. It is piobable thau ail
thefe iflands and rocks may in time be levelled by the
a&ion of the fea. Ponza, in its prelent ftate, is the
mere Ikeleton of a volcanic ifland 5 little more than its
hard or vitrified parts remaining, and they i'eem to be
flowly and gradually mouldering away. The governor
of the caftle of Ponza, who had reiided there 53 years,
told our author that the ifland was ftih fubject to earth¬
quakes ; that there had been one violent fhock there
about four years befoie ; but that the moil vio.ent one
he ever felt was on the very day and at the hour that
JLilbou was deftroyed. Two houfes outof three which
were then on the ifland were thrown down. “ 'Ibis
(fays our author) feems to prove that the volcanic mat¬
ter which gave birth to thefe iflands is not exhantted.
j. Plate CCLCXII. is a« plan ot the ifland ot
Ponza as it is given in the Philofophical x ranfactions.
Fig. 2. is a view of the inlide of the haioour ot the
ifland. A in the fame figure is a rock of lava. In
many parts it is formed into regular bafaltes of a reddifh
colour, tinged in all probability with fome ochre. Moil
of the detached rocks of the ifland reftmble this. BB
reprefents a trad of volcanic country, converted by a
hot fulphureous vitriolic acid vapour into a pure clay,
•the ground colour of which is moftly white.—Fig. 3. is
a view from the outfide of the harbour, near the light-
houfe. C is a rock of volcanic matter converted to
pure clay; D is a rock of the fame kind, with ftrata
of pumice-ftone : E is a rock of lava, inclining to take
baialtic forms ; and F is a rock compofed of fphencal
bafaltes.
POOD is a Ruffian weight, equal to 40 Ruffian or
36 Euglifh pounds. _
POOL is properly a refervoir of water fupplied with
fprings, and difeharging the overplus by flukes, defend
ders, weirs, and other caufeways.
Pool, a fea-port tqwn of Dorfetfhire in England.
It is furrounded on alllides by the fea, except on the
north, where there is an entrance through a gate. It
was formerly nothing but a place where a few fifher-
men lived : but in the reign of Henry VI. it was greatly-
enlarged, and the inhabitants had the privilege to wail
it round. It was alfo made a county of itfelf, and fent
two members to parliament. It is governed by a mayor,
a fenior bailiff, four other juftices, and an indeterminate
number of burgeffes. The town conflfts ot a church
and about 600 houfes, with broad paved ftreets; and
has a manufadtory of knit hofe. It is 47 miles weft-
fouth-weft of Winchefter, and no weil-by-iouth of
London. W. Long. 2. o« N. Lat. 50. 42..
POOLE (Matthew), a very learned writer m the
17th century, was born at York in 1624. He was
educated at Emanuel-college, Cambridge, and after¬
wards incorporated in the univeifity ot Oxford. He
fucceeded Dr Anthony Puckney in the redory ot bt
Michael de Quern, in London, about 1648. In 1 °5‘A
s A-' - a k®
Fotk*
11
Pool*.