LAT 
Diailciphia Decandrra class and drder. Na- 
tural order of Papilioiiacea; or Leguminosae. 
Essential character : calyx two, upper seg- 
ments shorter ; style flat, villose above, 
broader at the end. There are twenty- 
three species, among which is the L. odora- 
tus, sweet lathynis, or sweet pea, as it is 
commonly called, is an annual plant, about 
three feet in height, attaching itself to the 
nearest plant, by means of its long claspcrs 
or tendrils, the flower stalks come out at the 
joints, which are about six inches long, sus- 
taining two large flowers, possessing a 
strong odour ; these are succeeded by ob- 
long hairy pods, having four or five roundish 
seeds in ^ch. There are many varieties, 
according to Linnaeus the common dark 
sort is a native of Sicily, and the painted 
lady of Ceylon. 
LATITAT, in law', a writ, which in per- 
sonal actions is the commencement of a suit 
in the King’s Bench, where the party is to 
be arre.sted in any other county than Mid- 
dlesex. 
LATITUDE, the distance of a place 
from tlie equator, or an arc of the meridian 
intercepted between the zenith of the place 
and the equator. Hence latitude is either 
northern or southern, according as the 
place, whose latitude is spoken of, is on 
this or that side of the equator. ' Thus Lon- 
don is said to be in fifty-one degrees thirty- 
two minutes north latitude. Circles paral- 
lel to the equator, are called parallels of la- 
titude, because they shew the latitudes of 
places by their intersection with the meri- 
dian. If through the poles of the world we 
conceive innumerable great circles drawn, 
these are called secondaries of the equator, 
and by their help, the position of every 
point, either on earth or in the heavens, 
with regard to the equinoctial ; that is, the 
latitude of any point is determined. One 
of the secondaries, passing through any 
place on the earth’s surface, is called the 
meridian of that place, and on it the lati- 
tude of that place is measured. The lati- 
tude of a place, and the elevation of the 
pole of that place above the horizon, are 
terms used indift'erently for each other, be- 
cause the latitude and elevation of the pole 
are always equal. The knowledge of the 
latitude of a place is of the utmost conse- 
qtience in navigation ; and the methods of 
determining it, both at sea and land, are 
generally the same. As the altitude of the 
pole is always equal to the* latitude, the la- 
titude is consequently best found by ob- 
serving the pole’s height ; but as the imie is 
LAT 
only a mathematical point, and no ways to 
be observed by our senses, its height cannot 
be determined in the same manner as that 
of the sun and stars, &c. ; for which reason 
another manner has been contrived. A me- 
ridian line is first drawn, on which is placed 
a quadrant, so that its plane may be in the 
plane of the meridian ; then .some star near 
the pole is taken ; for example, tlie pole 
star, (which never sets) and observation is 
made of both its greatest and least altitude. 
The latitude may also be found by having 
the sun or a star's declination and meridian 
altitude, taken with a quadrant or astro- 
labe. The method is this : observe the me- 
ridian and distance of the sun from the ver- 
tex or zenith, which is always the comple- 
ment of his meridian altitude ; correct for 
the dip of the horizon, refraction, and add 
to this tl'.e sun’s declination, when the sun 
and the place are on the same side of the 
equator ; and subtract the declination when 
they are of dilferent sides ; the sum, in the 
former case, and the difference in the lat- 
ter, will be the latitude required. But 
when the declination of the sun is greater 
than the latitude of the place, which is 
known from the sun's being nearer to the 
elevated pole than the vertex of the place 
is, as it frequently happens in the torrid 
zone, then the difference between the sun’s 
declination and his zenith distance, is the 
latitude of the place. If the sun or star 
have no declination, hut move in the equi- 
noctial that day, then the elevation of the 
equator will be equal to his meridian alti- 
tude, and consequently his meridian alti- 
tude is the complement of the latitude to 
ninety. 
Latitude, in astronomy, the distance of 
a star or planet from the ecliptic, in de- 
grees, minutes, and seconds, measured on a 
circle of latitude drawn through that stat- 
or planet, being either north or south, as 
the object is situated either on the north or 
south side of the ecliptic. The ecliptic be- 
ing drawn on the common celestial globes, 
we may see what constellations it passes 
through : there are usually six circles of la- 
titude, w'hich, by their mutual intersections, 
show the poles of the ecliptic, as well as di- 
vide it into twelve equal part^, answerable 
to the number of months in a year. 
LATTEN, denotes iron plates tinned 
over, of which tea-canisters are made. 
Plates of iron being prepared of a proper 
thinness, are smoothed by rusting them in 
an acid liquor, as common water made ea- 
ger with rye ; with tins liquor they fill cer- 
