ROL 
R OP 
602 ROL 
florets are bundled in a head with scales in- 
terposed ; cal. partial, two-valved, one-fiow- 
rred ; corollets hermaph. There is one spe- 
cies, a shrub of the West Indies. 
ROLL, in manufactories, something 
wound and folded up in a cylindrical form. 
Few stuffs are made up in rolls, except 
sattins, gawses, and crapes, which are apt to 
break, and take plaits not easy to be got 
out, if folded otherwise. Ribbons, laces, 
galloons, and paduas ot all kinds, are also thus 
rolled. 
A roll of tobacco is tobacco in the leaf, 
twisted on the mill, and wound twist over 
twist, about a stick or roller. A great deal 
of tobacco is sold in America in rolls of va- 
rious weights ; and it is not till its arrival in 
England, Spain, France, and Holland, that 
it is cut. A roll of parchment properly de- 
notes the quantity of sixty skins. 
The anti (Hits made all their books up in 
the form of rolls, and in Cicero s time the 
libraries consisted wholly of such rolls. 
Roll, in law, signifies a schedule or parch- 
ment which may be rolled up by the hand 
intothe form of a pipe. 
tn these schedules of parchment all the 
pleadings, memorials, and acts ot court, are 
tutered and tiled by the proper officer; 
which being done, they become records of 
the court. Of these there are in the exche- 
quer several kinds, as the great wardrobe- 
roll, the cofferer’ s-roll, the subsidy-roll, &c. 
Roll is also used for a list of the names of 
persons of the same condition, or ot those 
who have entered into the same engagement. 
Thus a court-roll of a manor, is that in which 
the names, rents, and services of each tenant 
are copied and inrolled. 
Roll muster, that in which are entered 
the soldiers of every troop, company, regi- 
ment, &c. 
As soon as a soldier s name is written down 
on the roll, it is death for him to desert. 
Rolls-office, is an office in Chancery- 
lane, London, appointed for the custody of 
the rolls and records in chancery. 
Rolls of parliament, are the manuscript 
registers, or rolls of the proceedings of our 
antient parliaments, which before the inven- 
tion of printing, were all engrossed on parch- 
ment, and proclaimed openly in every coun 
t.y. In these rolls are also contained a great 
many decisions of difficult points of law* 
which were frequently in former times refen 
ed to the decision of that high court. 
Roll, or Roller, is also a piece of wood, 
iron, brass, &c. of a cylindrical form, used 
in the construction of several machines, and 
in several works and roanuiactures. 
‘ A rolling-mill shewn in fig. 4. Plate, 
consists of two iron rollers AB, mounted in a 
strong iron frame, which consists of two dis- 
tinct parts DE, both firmly fixed to the iron 
floor F; each part has a long mortice 
through it, in the bottom of which is the 
brass socket for the pivot of the roller A, and 
in the upper part is the brass of the upper 
roller ; this last brass is. fixed to a piece of 
iron G fig- 5, which slides up and down in 
the mortice, and is prevented from raising by 
the end of a strong screw a, screwed through 
the upper part of the frame D ; the roller 
is prevented from falling by its own weight 
by the brass l in the under side of the pivot, 
which is attached by two screw-bolts dd to 
a collar upon the screw a,, so that when the 
R O O 
screws are turned by a handspike put be- 
tween the teeth of the wheel II, the roheis 
A and B may be brought nearer together or 
further off, as occasion requires, 1 is a stout 
iron bar, fixed between the frames 1)E by a 
wedge i at each end, so that its upper sur- 
face is level with the top of the lower roller ; 
at a small distance above this, ts anothei bar 
k, fixed by two screws, between these are laid 
several blocks of iron L, so as to fill up a t 
the space, except a small opening, through 
which the bar to be flatted is introduced ; 1 
is a small trough of iron plate, bored full of 
holes, to which, water is brought by a small 
pipe p. The upper roller is put in motion by 
a strong shaft R, which conveys the power 
from a water-wheel, steam engine, &c. , and 
the lower one is moved by a cog-wheel S, 
on the shaft R, which turns another 1 , on the 
axis of the lower roller. The machine is 
placed near to a furnace, where the iron 
oars to be rolled, are heated to a welding 
heat; the mill is then put in motion, and the 
iron bars taken out, with a pair of pincher.-, 
and their ends put through the opening be- 
tween the bars K and L, between the rolleis , 
which as they turn round squeeze the iron 
flat, and to the proper thickness throughout, 
while other men behind the machine, convey 
it away, lhe rollers can be set nearer oi 
further off by turning the screws a a as before 
described. ‘The rolling-mill is principally 
used for making hoops lor barrels, and iion 
plates; the water brought by the pip up is to 
prevent the roller from being heated by the 
iron. 
ROLLER, in surgery, a long and broad 
bandage, usually of linen-cloth, rolled lound 
any part of the body, to keep it in, or dispose 
it to a state of health. 
KONDELETIA, a genus of tire mono- 
gvnia order, in the pentandria class of plants, 
and in the natural method ranking with those 
of which the order is doubtful. The corolla 
is funnel-shaped; the capsule bilocular, infe- 
rior, and polyspennous, roundish, and crown- 
ed. There are 14 species, shrubs of the W est 
Indies. , , . t 
ROOD, a quantity of land equal to forty 
square perches, or the fourth part ot an acre. 
ROOF. See Architecture. 
ROOK, in ornithology. See Corvus. 
ROOT. See Plants, physiology of . 
Root, in mathematics, a quantity considered 
as the basis or foundation of a higher power ; 
or one which being multiplied into itself any 
number of times, produces a square, cubic, bi- 
quadratic, &e. quantity; called the second, 
third, fourth, &c. power of the root, or quan- 
tity, so multiplied into itself ; thus a is the 
square root of a X a i or a * 5 an J^ 4 the square 
root of 4 x 4 m 16. Again, a is the cube-root 
oi a X a* a =i a'-, and 3 the cube-root of 
3 X 3 X 3 — 27 • and so on. See Algebra. 
The roots of powers are expressed by placing 
the radical sign \/ ~ over them, with a number 
denoting what kind of root they are : thus the 
square or second root of 16 is expressed by 
y/ 2 16, and the cube or third root of 27 by 
JW-, and, in general, the «th root of a raised 
to the power m, is expressed by When 
the root of a compound quantity is wanted, the 
vinculum of the radical sign must be drawn over 
the whole : thus t he square root of a 1 - \-2ab-f-b 
is expressed by 2 /* 2 + 2«* + ^5 and it ought 
to be observed, that when the radical sign has 
no number above it, to denote what root is 
] wanted, the square root is always meant ; s# 
| yV," or y'lC, is the square root of a 2 , or the 
square root of 16. 
ROPE, hemp, hair, &c. spun into a thick 
yarn, and then several strings of this yaili 
twisted together by mebns of a wheel. When 
made very small it is called a cord, und when 
very thick, a cable. All the different kinds 
of this manufacture, from a fishing-line or 
whip-cord to 'the cable, oi a first-rate ship of 
war, go by the general name of cordage. 
Ropes are made of every substance that is 
sufficiently fibrous, liexibie, and tenacious, 
but chiefly of the inner barks of plants. The 
Chinese and other orientals even make them 
of the ligneous, parts of several plants, such 
as certain bamboos and reeds, the stems ot 
the aloes, the fibrous covering of the cocoa- 
nut, the 'filaments of the cotton pod, and the 
leaves of some grasses, such as the sparfe 
(lygenm, Linn.). The aloe (agave, Linn.) 
and the sparte exceed all others in strength. 
But the barks of plants are the most produc- 
tive ot fibrous matter fit for this manufacture. 
Those of the linden tree (tilia) of the willow, 
the bramble, the nettle, are frequently used ; 
but hemp and flay are the best; and of these 
the hemp is preferred', and employed in all 
cordage exceeding the size ot a line, and 
even in many of this denomination. 
Hemp is very various in its useful qualities;, 
the best in Europe comes to us thro gh Riga, 
to which port it is brought from very distant 
places southward. It is known by the name- 
of riga rein (that is, clean) liemix Its fibre 
is not the longest (at least in the dressed state 
in which we get it) but it is the finest, rqost 
flexible, and strongest, lhe next to this is 
supposed to be the' Petersburg!! braak hemp. 
Other hemps are esteemed nearly in the fol- 
lowing order: Riga outshot, Petersburg out- 
shot, “hemp from Koningsburgh, Archangel, 
Sweden, Memel. Chucking is a name given 
to a hemp that comes from- various places, 
long in the fibre, but coarse and harsh, and 
its strength is inferior to hemps which ap- 
pear weaker. Its texture is such, that-it does 
not admit splitting with the hatchel, so as to 
be more completely dressed: it is therefore 
kept in its coarse form, and used for inferior 
cordage. It is, however, a good and strong 
hemp, but will not make fine work. There 
are doubtless many good hemps in the south- 
ern parts ot Europe; but little- of them is 
brought to our market. Codilla, half clean. 
Sec. lire portions of the above-mentioned 
hemps, separated by the dressing, and may 
be considered as broken fibres of those 
hemps. 
Only the first qualities are manufactured 
for the rigging of the royal navy and for the 
ships of the East India company. 
ROPE-MAKING, is an art of very great 
importance; and there are few that better 
deserve the attention of the intelligent ob- 
server. Hardly any art can be carried on 
without the assistance of the rope-maker. 
Cordage makes the very sinews and muscles 
of a ship; and every improvement which 
can be made in its preparation, either in re- 
spect to strength or pliableness, must be of 
immense service to the mariner, and to the 
commerce and the defence of nations. 
The aim of the rope-maker is to unit ? the 
strength of a great number of fibres. This* 
would be done in the completest manner by 
