SO LON 
still farther improved under his direction, by 
the late Mr. Charles Mason, by several new 
equations, and the whole computed to tenths 
of a second. These tables, when com- 
pared with the above-mentioned series of ob- 
servations., a proper allowance being made for 
the unavoidable error of observation, seem to 
give always the moon’s longitude in the hea- 
vens correctly within 30 seconds of a degree; 
which greatest error, added to a possible 
error ot one minute in taking the moon’s 
distance from the sun or a star at sea, will at 
a medium only produce an error of 42 mi- 
nutes of longitude. To facilitate the use of 
the tables. Dr. Maskelyne proposed a nau- 
tical ephemeris, the scheme of which was 
adopted by the commissioners of longitude, 
and first executed in the year 1767, since 
which time it has been regularly continued. 
But as the rules that were given in the ap- 
pendix to one of those publications, for cor- 
recting the effects of refraction and parallax, 
were thought too difficult for general use, 
they have been reduced to tables. So that, 
by the help of the ephemeris, these tables, 
and others that are also provided by the 
board of longitude, the calculations relating 
to the longitude, whph could not be per- 
formed by the most expert mathematician 
in less than four hours, may now be com- 
pleted with great ease and accuracy in half 
an hour. 
As this method of determining the longi- 
tude depends on the use of the tables an- 
nually published for this purpose, those who 
wish for farther information are referred to 
the instructions that accompany them, and 
particularly to those that are annexed to the 
tables requisite to be used with the Astro- 
nomical and Nautical Ephemeris. 
4th. The phenomena of Jupiter’s satellites 
have commonly been preferred to those of 
the moon, for finding the longitude; because 
they are less liable to parallaxes than these 
arej and besides they afford a very commo- 
d.ious observation whenever the planet is 
above the horizon. Their motion is very 
-swift, and must be calculated for every hour. 
Now, to find the longitude by these satel- 
lites: with a gooxl telescope observe some of 
their phenomena, as the conjunction of two 
of them, or of one of them with Jupiter, &c. 
and at the same time find the hour and mi- 
nute, from the altitudes of the stars, or by 
means of a clock or watch, previously regu- 
lated for the place of observation; thqn, con- 
sulting tables of the satellites, observe the 
time when the same appearance happens in 
the meridian of the place for which the tables 
are calculated; and the difference of time, as 
before, will give the longitilde. 
The eclipses of the first and second of Ju- 
piter’s satellites are the most proper for this 
purpose; and as they happen almost daily, 
they afford a ready means of determining the 
longitude of places at land, having indeed 
contributed much to the modern improve- 
ments in geography; and if it were possible 
to observe them with proper, telescopes, in 
a ship under sail, they would be of great ser- 
vice in ascertaining its longitude from time 
to time. To obviate the inconvenience to 
which these observations are liable from the 
motions of the ship, Mr. Irwin invented 
■what he called a marine chair : this was tried 
sby Dr. Maskelyne, in his voyage to Barba- 
L O O 
doe?, when it was found that no benefit 
could be derived from the use ot it. And 
indeed, considering the great power requi- 
site in a telescope proper for these observa- 
tions, and the violence as well as irregulari- 
ties in the motion of a ship, it is to he feared 
that the complete management of a telescope 
on shipboard will always remain among the 
desiderata in this part of nautical science. 
And farther, since all methods that depend 
oil the phenomena of the heavens, have also 
this other defect, that they cannot be ob- 
served at all times, this renders the improve- 
ment of timekeepers of the greater impor- 
tance. 
TONIC EE A, honeysuckle, a genus of the 
monogynia order, in the pentandria class of 
plants. The corolla is monopetalous and ir- 
regular ; the berry polyspermous, bilocular, 
and inferior. There are 19 species, of which 
the most remarkable are, 
1. The alpigena, or upright red-berried 
honeysuckle, rises with a shrubby, short, up- 
right stem, four or five feet high. 
2. The cserulea, or blue-berried honey- 
suckle, with a shrubby upright stem, three 
or four feet high, and many while flowers 
proceeding from the sides of the branches. 
3. The nigra, or black-berried upright 
honeysuckle, with a shrubby stem three or 
four feet high, and white flowers succeeded 
by single and distinct black berries. 
’ 4. The tartarica, or Tartarian honeysuckle, 
with a shrubby upright stem, three or four 
feet high, heart-shaped opposite leaves, and 
whitish erect flowers succeeded by red ber- 
ries, sometimes distinct, and sometimes 
double. 
5. The diervilla, or yellow-flowered Arca- 
cadian honeysuckle, with shrubby upright 
stalks, to the height of three or four feet, 
and clusters of pale yellow flowers, ap- 
pearing in May and June, and sometimes 
continuing till autumn, but rarely ripening 
seeds here. 
6. The xylosteum, or fly honeysuckle, 
with a strong shrubby stem, branching erect 
to the height of seven or eight fret, and erect 
white flowers proceeding from the sides of 
the branches. 
, 7. The symphoricarpos, or shrubby St. 
Peter’s-wort, with a shrubby rough stem, 
four or five feet high, and small greenish 
flowers. 
8. The periclymenum, or common climb- 
ing honeysuckle, has two principal varieties, 
viz. the English wild honeysuckle, or wood- 
bine of our woods and hedges, and the Dutch 
or German honeysuckle, with a shrubby de- 
cimated stalk, and long trailing purplish 
branches, furnishing large beautiful red flow- 
ers of a fragrant odour, appearing in June 
and July. 
9. The caprifolium, or Italian honeysuckle, 
with shrubby decimated stalks, sending out 
long slender trailing branches, terminated by 
verticillate or whorl ed bunches of close-sit- 
ting flowers, very fragrant, and white, red, 
and yellow colours. 
10. The sempervirens, or evergreen trum- 
pet-flowered honeysuckle, with a shrubby 
decimated stalk, sending out long slender 
trailing branches, terminated by naked ver- 
ticillate spikes, of long, unrefiexed, deep- 
scarlet flowers, very beautiful, but of little 
fragrance. 
LOOT, in the sea language, is a term used 
LOO 
in various senses; thus the loof of a ship is 
that part of her aloft which lies just before 
the chest-tree ; hence the guns which lie 
there are called loof-pieces: keep your loof, 
signifies, keep the ship near to the wind: to 
loof into a harbour, is to sail into it close by 
the wind: loof up, is to keep nearer the 
wind: to spring the loof, is when a ship that 
das going large before the wind, is brought 
close by the wind. 
Loof-tackle, is a tackle in a ship which 
serves to lift goods of small weight in or out 
of her. 
LOOKING-GLASSES. See Optics. 
LOOM, the weaver’s frame, a machine 
whereby several distinct threads are woven 
into one piece. Looms are of various struc- 
tures, accommodated to the various kinds of 
materials to be woven, and the various man- 
ner of weaving them, viz. for woollens, silks, 
linens, cottons, cloths of gold, and other 
works, as tapestry, ribands, stockings, &c. 
See Weaving. 
The weaver’s loom-engine, otherwise called 
the Dutch loom-engine, was brought into use 
from Holland to London, in or about the 
year 1676. 
The lower compartment of Plate Lock and 
Loom, represents a loom for weaving silks or 
other plain work. A, fig. 6, is a roll called the 
cloth-beam, on which the cloth is wound as it 
is wove ; at one end it has a racket-wheel a , 
and a click to prevent its running back ; at 
the same end it has also four holes in it, and 
is turned by putting a stick in these holes: at 
the other end of the loom is another roll B, 
on which the yarn is wound; this has two 
small cords hb wrapped round it, the ends of 
which are attached to a bar 4> which has a 
weight D hung to it ; by this means a fric- 
tion is caused, which prevents the roll B turn- 
ing by accident. EF are called lambs; they 
are composed of two slicks efhi, between 
which are fastened a great number of threads ; 
to the bar e are fastened two cords gh, which 
pass over pulleys, and are fastened to the bar 
h of the lamb F ; the lower bars of each lamb 
are connected by cords with the treadles GH ; 
the workman sits on the seat K, and places 
his feet upon these treadles; as they are con- 
nected together by the cords gh, when he 
presses down one, it will raise the other, and 
the lambs with them; a great number of 
threads, according to the width of the cloth, 
are wound round the yarn-beam B, and are 
stretched to the cloth-beam A; the middle 
of the threads which compose the lamb EF, 
have loops (called eyes) in them, through 
which the threads between the roils AB, 
which are called the warp, are passed; the 
first thread of the warp goes through the 
loops of the lambs E, the next attached to 
the lamb F, and so on alternately ; by this 
means, when the leaver presses down one of 
the treadles with his foot, and raises the 
other, one lamb draws up every other thread, 
and the other sinks all the rest, so as to make 
an opening between the sets of thread: EL 
is a frame moving oji a centre at the top of 
the irame of the loom; the lower part of 
this frame is shewn in fig. 8 ; LL are the two 
uprights of the frame, / is the bar that con- 
nects them, M is a frame carrying a great 
number of pieces of split reed or sometimes fine 
wire at equal distances; between these the 
threads of the warp are passed ; the frame M 
is supported by a piece of wood m called the 
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