Encyclopaedia Britannica, or, a Dictionary of arts, sciences, and miscellaneous literature : enlarged and improved. Illustrated with nearly six hundred engravings > Volume 20, SUI-ZYM

YEN [ 540 ] YEN
Venice adjacent canal, and another to the ftreet. As the nar-
Vent-Ltor rowne^s ^ie ftreetfi but ill adapts them for walking in,
. ^ the only places of refort on land are the Rialto, a noble
bridge acrofs the great canal, bordered with booths and
Iho] >s, and the great fquare of St Mark, or Piat&Ka di
St Marco, an irregular quadrangle, formed of feveral
buildings, fome of which are magnificent. Of thefe,
the ducal palace, where the bufinels of the Hate uled to
be tranfafted 5 the patriarchal church of St Mark ; the
fteeple of St Mark, at a little diitance from the church }
the church of St Geminiano 5 and the new and old
Procuraries, are molt deferving the notice of travellers.
The canals form the great medium of communication,
as well as the principal fcene of relaxation and amufe-
ment to the inhabitants. Here ply numerous gondolas,
(fee Gondola, and Macgill's Travels, vol. i.) which
are rowed with admirable fpeed and dexterity by the
gondoliers 5 and here are occafionaily held races, or ra¬
ther rowing matches. As the canals are, of neceflity,
the receptacles of all the filth of the city, they become,
in hot weather, very offenfive j while, in winter, from
their free communication with the gulf, they are fre¬
quently agitated by the Adriatic florms. The whole
city i.‘ about fix miles in circumference, and the inha¬
bitants are eftimated at 160,000.
The inhabitants of Venice carried on a flourifhing
trade in filk manufactures, gold lace, mirrors and other
articles of glafs, beiides military ttores and implements
of war. At fome dillance from the city there is a large
and commodious lazaretto, where (hips coming from the
Levant unload their goods, and perform quarantine
from 20 to 40 days.
This celebrated city, once the feat of power, opu¬
lence and the fine arts, whofe carnival revelries have
been the fubjedl of fo many animated defcriptions, lias
undergone a melancholy change. Her ftreets and ca¬
nals no longer refound with the ftrains of the mufician
and the ferenades of watchful lovers, and her gay gon¬
dolas, which were formerly occupied by fafhionable
groups and parties of pleafure, are now become the •ve¬
hicles of trade, or ferve for the accommodation of the
foldier and the mechanic. The trade of the city, which
had long declined, has, fince the ceflion of the Venetian
territory to Auftria, been almoft entirely transferred to
Triefte. Venice is 72 miles E. by N. of Mantua 5115
N. E. of Florence *, 140 E. of Milan •, 212 N. of Rome,
and 300 N. by W. of Naples. E. Long. 120 33'. Ni
Lat. 450 26'.
VENIRE facias, in Law, is a judicial writ lying
where two parties plead and come to iffue, direfted to
the (heriff, to came 1 2 men of the fame neighbourhood
to meet and try the fame, and to fay the truth upon the
ifiue taken.
VENTER, fignifies the belly ; but it is alfo ufed for
the children by a woman of one marriage : there is in
law a firll and fecond venter, &c. where a man hath
children by feveral wives j and how they (hall take in
defcents of lands.
VENTILATOR, a machine by which the noxious
air of any clofe place, as an hofpital, gaol, Ihip, cham¬
ber, &c. may be difcharged and changed for frefh.
I he noxious qualities of bad air have been long
known ; and no one has taken greater pains to fet the
mifchiefs arifing from foul air in a juft light than Dr
Hales } who has alfo propofed an eafy and effectual re-
1
medy by the ufe of his ventilators 5 his account of which Ventilate
was read to the Royal Society in May 1741. In the U“Y’--
November following M. Triewald, military architeft to
the king of Sweden, informed Dr Mortimer fecretary
to the Royal Society, that he had in the preceding fprir,<f
invented a machine for the ufe of his majefty’s men of
war, in order to draw out the bad air from under their
decks, the leaft of which exhaufted 36,172 cubic feet
in an hour, or at the rate of 21,732 tons in 24 hours.
In 1742 he fent one of them, formed for a 60 gun fhip
to France ; which was approved of by the Roval Aca¬
demy of Sciences at Paris 5 and the king of France or¬
dered all the men of war to be furniftied with the like
ventilators.
The ventilators invented by Dr Hales confift of a piate
fquare box ABCD (fig. r.) of any fize j in the middle DXllv
of one fide of this box a broad partition or midriff is fix- 1*
ed by hinges X, and it moves up and down from A to
C, by means of an iron rod ZR, fixed at a proper di-
ftance from the other end of the midriff, and palling
through a fmall hole in the cover of the box up to II.
Two boxes of this kind may be employed at once, and
the two iron rods may be fixed to a lever EG (fig. 2.) Fig. 2.
moving on a fixed centre O ; fo that by the alternate
railing and prelTmg down of the lever EG, the midriffs
are alfo alternately raifed and depreffed, whereby thefe
double bellows are at the fame time both drawing in air,
and pouring it out, through apertures with valves made
on the fame fide with, and placed both above and be¬
low the hinges of the midriffs. In order to render the
midriffs light, they are made of four bars lengthwife,
and as many acrofs them breadthwife, the vacant fpapes
being filled up with thin pannels of fir board j and that
they may move to and fro with the greater eafe, and
without touching the fides of the boxes, there is an iron
regulator fixed upright to the middle of the end of the
box AC (fig. I.) from N to L, with a notch cut info
the middle of the end of the midriff at Z ; fo that the
midriffs, in riling and falling, fuffer no other fricliou
than what is made between the regulator and the notch.
Moreover, as the midriff ZX moves with its edges only
one-twentieth of an inch from the fides of the box
ABCDFE, very little air will efcape by the edges j
and, therefore, there will be no need of leathern fides as
in the common bellows. The end of the box at AC is
made a little circular, that it may be better adapted
between A and C to the riling and falling midriff; and
at the other end X of the midriff a flip of leather may
be nailed over the joints if needful. The eight large
valves through which the air is to pafs, are placed at
the hinge-end of the boxes BK (fig. 2.) as at 1, 2, 3,
&c. The valve I opens inw7ard to admit the air to
enter, when the midriff is depreffed at the other end
by means of the lever EG. And at the fame time the
valve 3 in the knver ventilator is Unit by the comprefled
air which paffes out at the valve 4. But when that
midriff is raifed, the valve 1 flmts, and the air paffes
out at the valve 2. And it is the fame with the valves
5, 6, &c. of the other box 5 fo that the midriffs are al¬
ternately riling and falling, and two of the ventilators
drawing in air, and two blowing it out ; the air enter¬
ing at the valves 1, 3, 6, 8, and pafling out at the valves
2, 4, 5, 7. Before thefe laft valves there is fixed to the
ventilators a box (^QNM (fig. 3.) as a common recep-Fig-3>
tacle for all the air which comes out of thefe valves;
which