~ 
AS 
ferable. In this cafe, one of the move- 
able extremes, namely, either the crown 
of the bow, or middle point of its ftring, 
is to be fixed to the upper hook or place 
of fufpenfion, end the bed itfelf' is fixed 
to the other moveable extremity, viz. the 
middle point of the ftring, or the crown 
of the bow, as it may° happen. And in 
order that the perfon in the faid bed 
may produce at pleafure the before-de- 
fcribed motion, a pulley is fixed at, 
er near, the center of fufpenfien, thro’ 
which a cord is paffed, having one-end of 
“it attached to the bed, and the other at 
‘Hberty to be drawn by the perfon or ‘af- 
fiftant, to produce the motion. There 
are contrivances alfo to prevent the'fpring 
from giving way. | 
This patent includes the conftruétion of 
cradles, or {mall beds for children ;—the 
method of fufpending fofas,chairs and other 
feats, with or without: moveable backs, 
for the repofé of the human body. The 
fefpenfion is peculiarly adapted ‘fer the 
fupport of broken limbs, and various 
other ufeful purpofes. 
31R. WILLIAM CHAPMAN's €NEW- 
CASTLE-UPON-TYNE) for the APPLI- 
CATION of certain SUBSTANCES, either 
feparately or combined, as @ PRESER- 
VATIVE of: CORDAGE. 
Tt'is a well-known faét, that common 
tar, unprepared, contains a quantity of 
vegetable acid, that is found materially to 
‘injure the cordage to which it is applied. 
Mr. Chapman’s fpecification deferibes a 
methcd of extraéting the mucilage and 
‘acid from taf, or any other refinous matter, 
before itis uled. 
The rope-manufaéturer may purfue the 
common procefles of the tar-diftillers ; or 
he may wafh the tar by agitations im cold, 
warm), or hot water ; or he may boil it in 
water, which, in the a€tion.of ebullition, 
will agitate and wath the tar, and after it 
has parted with a fufficient portion of its 
elfential cil, he may feparate it from the 
water, and afterwards pafs his yarns 
through it, in fuch adegree of tempera- 
ture as he may fee expedient: the eflen- 
tial oil may be faved, by putting upon his 
kettle the head of a ftill, with its appa- 
ratus. 
After the tar is purified, the water muft 
be poured away, and the tar be boiled a 
dittle time to throw off any that may 
ftillyemain mixed with it, The opera- 
tion fhould be performed more than once, 
is great purity be required. 
This invention goes allo to the carrying 
foiward the improvement of the rope, im- 
New Patents lately enralied. 
[Feb. i, 
mediately previous te, or during the put- 
‘ting of its ftrands together. In the ufual 
method the fopi(an inftrument which fe- 
parates the firands until the inftant ‘of 
their combining into a rope) is made to 
_flide uniformly, and without jerks, by 
rubbing a piece of tallow along each of . 
the ftrands. In the place of tallow, the 
following compofition .is recommended, 
two parts of tallow and one of rofin, 
Thefe proportions muft be varied accord- 
ing to the temperature of the weather, é&c. 
— ia 
MR. JOHN WHITLEY BOSWELL’s (DUB- 
LIN) for @ METHOD of BUILDING or 
FaBRICATING SHIPS or VESSELS for 
NAVIGATION. ; 
This method differs principally from 
that in ule, by placing timbers or ribs, 
lengthwife or horizontally, inftead of ver- 
tically ; and in making ufe of a frame, 
confiltisg of a feries of triangles, in cer- 
tain parts of the veffel, either to produce 
a greater degree of ftrength, with the 
fame quantity of materials, or an equal 
ftrength with a imaller quantity. By 
whicn it is expected, that much lefs 
crooked timber need be ufed than is now 
employed, and the danger of ufing pieces 
cut acro{s the grain proportionally dimi- 
‘ nifhed. ur 
In this fpecification are given very par- 
ticular directions for conftruting veffels, 
and all the material parts of them, fepa- 
rately, fuch as the head and ftern; the 
keel and kelfon ; the intervals between 
the horizontal ribs, and the decks. The 
patentee adds, that it is his intention, that 
every part and thing, of and about a vef- 
fel, not defcribed by him, fhould be made 
or done according to the method in ge- 
neral ufe. . 
Befides the advantages of ftrength gained, 
expencefaved,and a diminution of the nece[- 
fary conf{umption of crooked timber, Mr. 
“Bofwell propofes,as an additional feeurity, 
that the planks ‘ufed,. fhould be grooved 
at their edges, in fuch a manner that 
when they are put together the grooves 
may he oppofite to each other; and that 
narrow flips of durable wood be placed in 
the faid grooves, fo as to lie acrofs the 
feams, the whole length of the plank, but 
of fuch a fize as to leave fufficient {pace 
on the outfide of them for caulking. It 
is imagined that thefe flips will have the 
effect of valves, to prevent the farther 
progrefs of any water that paffes the 
ozkum, tending to clofe the paflage more 
tightly the more they are prefled by the 
external water. . : 
’ REVIEW: 
