ROP ROS 
which is sometimes very difficult, espc- Such is the general and essential process of 
cially in ropes composed of more than rope-making. The fibres of hemp are 
three strands. It will greatly improve the twisted into yams, that they may make a 
laying the rope, if the top has a sharp, line of any length, and stick among each 
smooth, tapering pin of hard wood, pointed other with a force equal to their own cohe- 
at the end, projecting so far from the mid- sion. The yarns are made into cords of 
die of its smaller end, that it gets in between permanent twist by laying them ; and that 
the strands which are closing. This sup- 
ports them, and makes their closing more 
gradual and regular. The top, its notches, 
the pin, and the warp, or strap, which is 
lapped round the rope, are all smeared with 
grease or soap, to assist the closing. The 
foreman judges of the progress of closing 
chiefly by his acquaintance with the walk, 
knowing that when the sledge is abreast of 
a certain stake, the top should be abreast 
of a certain other stake. When he finds 
the top too far down the walk, he slackens 
the motion at the tackle-board, and makes 
the men tUrn briskly at the sledge. By 
this the top is forced up the walk, and the 
laying of the rope accelerates, while the 
sledge remains in the same place, because 
the strands are loosing their twist, and are 
lengthening, while the closed rope is shor- 
tening. When, on the other hand, he thinks 
the top too far advanced, and fears that it 
will be at the head of the walk before the 
sledge has got to its proper place, he makes 
the men heave briskly on the strands, and 
the heavers at the sledge crank work softly. 
This quickens the motion of the sledge by 
shortening the strands ; and by thus com- 
pensating what has been over-done, the 
sledge and top come to their places at once, 
and the work appears to answer the inten- 
tion. IVhen the top approaches the tackle- 
board, the heaving at the sledge cmild not 
cause the strands immediately behind the 
top to close well, without having previously 
produced an extravagant degree of twist in 
the intermediate rope. The effort of the 
crank must therefore be assisted by men 
stationed along the rope, each furnished 
with a tool called a woolder. This is a stout 
oaken stick, about three feet long, having a 
strap of soft rope-yarn or cordage, fastened 
on its middle or end. The strap is wrapped 
round the laid rope, and the workman 
works with the slick as a lever, twisting 
the rope round in the direction of the 
crank’s motion. The woolders should keep 
their eye on the men at the crank, and 
make their motion correspond with his. 
Thus they send forward the twist produced 
by the creiiik, without either increasing of 
diminishing it, in that part of the rope 
which lies between them and the sledge. 
we may have a rope of any degree of 
strength, many yarns are united in one 
strand, for the same reason that many fibres 
were united in one yarn ; and in the course 
of this process it is in our power to give the 
rope a solidity and hardness which make it 
less penetrable by water, which would rot 
it in a short while. Some of these pur- 
poses are inconsistent with others; and 
the skill of a rope-maker lies in making 
the best compensation, so that the rope 
may on the whole he the best in point of 
strength, pliancy, and duration, that the 
quantity of hemp in it can produce. The 
following rule for judging of the weight 
which a rope will bear is not far from the 
truth. It supposes them rather too strong; 
but it is so easily remembered, that it may 
be of use. Multiply the circumference in 
inches by itself, and take the fifth part of 
the product, it will express the tons which 
the rope will carry. Thus, if the rope has 
six inches circumference, 6 times 6 is 36, 
the fifth of which is 7i tons. 
Rope yarn, among sailors, is the yarn of 
any rope untwisted, but commonly made 
up of junk ; its use is to make sinnet, mats, 
&c. 
RORIDtJLA, in botany, a genus of the 
Pentandria Monogynia class and order. Es- 
sential character : calyx five-leaved ; eo- 
rolla five-petalled ; anthers scrotiform at 
the base ; capsule three-valved. There is 
but one species, viz. R. dentata, a native 
of the Cape of Good Hope. 
ROSA, in botany, the rose, a genus of 
the leosandria Polygynia class and order. 
Natural order of Senticosae. Rosace®, Jus- 
sieu. Calyx pitcher-shaped, five-cleft, fleshy, 
contracted at the neck ; petals five; seeds 
very many, hispid, fastened to the inner 
side of the calyx. There are forty spe- 
cies. 
ROSACIC acid. During certain diseases, 
the urine, when it cools, deposits a peculiar 
substance, which has been denominated, 
from its colour, which resembles bricks, la- 
teritious sediment. During fevers, this ap- 
pearance of the urine takas place ; and in 
gouty persons, at the termination of the pa- 
roxysms, it is very abundant. And when 
this suddenly disappears, and the urine at. 
