I 
ploy them merely to repel an assailant. Its 
principal food consists of the bark of trees, 
roots, and fruit, and is almost universally 
collected by it in the night. In the day it 
lies retired, and sleeping in a subterraneous 
habitation, which it is said to construct with 
particular ingenuity, dividing it into several 
apartments. It produces two at a birth, 
and if taken young is tamed with consider- 
able facility. Its flesh is eaten not only in 
Africa but in Italy, and is thought extreme- 
ly luscious, on which account it can be taken 
by few in any large quantify. See Mam- 
malia, Plate XII., fig, 3. 
H. prehensilis, or the Brazilian por- 
cupine. This is about a foot long, and its 
JAC 
tail about a foot and half, by which it clings 
to the branches of trees, and facilitates its 
object of attack or escape. It is covered 
with strong, short, and extremely sharp 
spines, on most of those parts of its body 
particularly exposed to assault. It is found 
in the warm climates of America, and par- 
ticularly in Brazil, where it inhabits the 
woods, and subsists not only upon fruits and 
vegetables, like the former species, but also 
on small birds. Its sounds resemble the 
grunting of a pig. It secludes itself during 
the day in the hollows '•of trees, or under 
their roots, and by night engages in its ex- 
cursions and repasts. See Mammalia, Plate 
XII. fig. 4. 
T or i, the ninth letter, and third vowel of 
-*■5 the alphabet, is pronounced by throw- 
ing the breath suddenly against the palate, 
as it comes ont of the larynx, with a small 
hollowing of the tongue, and neat ly the same 
opening of the lips as in pronouncing a ore. 
Its sound varies ; in some words it is long, 
as high, mind, & c. ; in others short, as hid, 
hid, sin, &c. ; in others again it is pronounced 
like y, as in collier, onion, &c. ; and in a few 
it sounds like ee, as in machine, magazine, 
&c. No English word ends in i, e being 
either added to it, or else the i turned 
into y. 
But besides the vowel, there is the jod 
consonant; which because of its different 
pronunciation, has likewise a different form, 
thus, J, j. In English it has the soft sound 
of g, nor is used but when g soft is required 
before vowels, where g is usually hard : thus 
we say jack, jet, join, &c. instead of gack, 
get, gain, &c. which would be contrary to 
the genius of the English language. 
I, used as a numeral, signifies no more 
than one, and stands for so many units as it 
is repeated times : thus I, one ; II, two ; 
III, three, &c. and when put before a higher 
numeral it substracts itself, as IV, four; 
IX, nine, &c.: but when set after it, so 
many are added to the higher numeral as 
there are I’s added: thus VI, is 5-J-l, or 
six ; VII, 5 -J- 2, or seven ; VIII, 5 + 3, or 
eight.- The ancient Romans likewise used 
10 for 500, CIO for 1,000, 100 for 5,000. 
CCIOO for 10,000, IOOO for 50,000, and 
CCCIOOO for 100,000. Farther than this, 
as Pliny observes, they did not go in their 
notation; but when necessary, repeated the 
last number, as CCCIOOO, CCCIOOO for 
200,000 ; CCCIOOO, CCCIOOO, CCCIOOO 
for 300,000 ; and so on. 
JACK, in mechanics, an instrument of 
common use for raising heavy timber, or 
very great weights of any kind. 
The common kitchen jack is a compound 
engine, where the weight is the power ap- 
plied to overcome the friction of the parts, 
and the weight with which the spit is charg- 
ed; and a steady and uniform motion is ob- 
tained by means of the fly. 
Jack, in naval affairs, a sort of flag, or 
colours, displayed from a staff erected on 
the outer end of a ship’s bowsprit. In the 
British navy the jack is a’ small union flag; 
but in merchant ships the union is bordered 
with red. 
Jack , smoke. See Smoke jack. 
Jack in the box, a large wooden male 
screw, turning in a female one, which forms 
the upper part of a strong wooden box, 
shaped like a frustrum of a pyramid. It is 
used by means of levers passing through 
holes in it, as a press in packing, and for 
other purposes. 
Jack block, a block occasionally attached 
