TAN 
downwards at their ends ; these are covered 
with a chesnut coloured bark, and garnish- 
ed with very narrow, finely-divided leaves, 
of a bright green colour, having small leaves 
or indentures, which lie over each other 
like scales offish ; file flowers are produced 
in taper spikes, at the end of the branches, 
several of them growing on the same 
branches ; the spikes are about an inch 
long, the flowers are set very close all 
round the spike ; they are small, and have 
five concave petals, of a pale flesh colour, 
with five slender stamina, terminated by 
roundish red anthers ; the flowers appear in 
July, and are succeeded by oblong, acute- 
pointed, three-cornered capsules, filled with 
small downy seeds, which seldom ripen in 
England. 
TAMBAC, a mixture of gold and cop- 
per, which the people of Siam hold more 
beautiful, and set a greater value on, than 
gold itself. 
TAMBOUR, in architecture, a term ap- 
plied to the Corinthian and Composite ca- 
pitals, as bearing some resemblance to a 
drum, which the French call tambour. 
Tambour is also used for a little box of 
timber-w'ork, covered with a ceiling, with- 
in side the porch of certain churches, both 
to prevent the view of persons passing by, 
and to keep off the wind, &c. by means of 
folding doors. 
TAMU.S, in botany, black bryony, a ge- 
nus of the Dioecia Hexandria class and or- 
der. Natural order of Sarmentaceaa. As- 
paragi, Jussieu. Essential character : ca- 
lyx six-parted ; corolla none : female, style 
trifid , berry three-celled, inferior ; seeds 
two. There are two species, viz. T. com- 
munis, common black bryony, and T. cre- 
tica, Creton black bryony. 
TANACETUM, in botany, a genus 
of the Syngenesia Polygamia Superflua class 
and order. Natural order of Compositse 
Discoidae. Corymbiferaj, Jussieu. Essen- 
tial character : calyx imbricate, hemisphe- 
rical ; corolla rays obsolete, trifid, some- 
times none, and all the flowers herr|iaphro- 
dite ; down submarginate : receptacle 
naked. There are nine species, of which 
the T. vulgare, common tansy, haS a fibrous 
creeping root, which spreads to a great dis- 
tance; the herb is bitter, possessing a 
strong aromatic smell. It is a native of 
Europe and Siberia, in high meadows and 
pastures, on the banks of livers, and in 
swampy places, flowering from June to Au- 
gust. 
TANAECIUMjin botany, a genus of the 
TAN 
Didynamia Angiospermia class and order : 
Essential character : calyx cylindrical, trun- 
cate ; corolla tubular, almost equal, five- 
cleft; rudiment of a fifth filament ; berry 
corticose, very large. There are two sjie- 
cies, viz. T. jaroba, and T. parasiticuin, 
both natives of Jamaica. 
TANAGRA, the tanager, in natural his- 
tory, a genus of birds of the order Passeres. 
Generic character: bill conicj somewhat 
inclining towards the point j upper mandi- 
ble slightly ridged and notched near the 
end. There are forty-four species, of which 
the following deserve the chief attention. 
T. jacapa, or the red-breasted tanager, is 
of the size of a sparrow, and abounds in va- 
rious parts of America. It feeds on fruits, 
and frequents gardens. Its nest is of a cy- 
lindrical form, fixed to the horizontal branch 
of a tree, and the entrance is beneath. It 
is generally seen in pairs. 
The T. tatoa, or titmouse of Paradise, is 
nearly as lai'ge as a goldfinch, is one of the 
most beautiful birds of the genus, adorned 
with the most brilliant plumage of scarlet, 
blue, green, and gold. It is found in flocks 
in Cayenne and Guiana, at the season when 
a particular, but undeseribed, fruit tree is 
in bearing, and is said to be found, in those 
countries, only in the immediate vicinity of 
these trees. It may be confined, and fed 
on bread and milk ; but has no powers of 
melody. 
Tangent, in geometry, is defined, in 
general, to be a right line, which touches 
any arch of a curve, in such a manner, that 
no ri;mt line can be drawn between the 
right line and the arch, or within the angle 
that is formed by them. The tangent of an 
arch is a right line drawn perpendicularly 
from the end of a diameter, passing to one 
extremity of the arch, and terminated by a 
right line drawn from the centre through 
the other end of the arch, and called the se- 
cant. ' And the co-tangent of an arch is the 
tangent of the complement of that arch#, 
The tangent of a curve is a right line which 
only touches the curve in one point, but 
does not cut it. • 
In order to illustrate the method of draw- 
ing tangents to curves, let A C G, Plate 
XIV. Miscel. fig. 10, be a curve of any 
kind, and C the given point from whence 
the tangent is to be drawn. Then con- 
ceive a right line, mg, to be carried along 
uniformly, parallel to itself, from A towaids 
Q ; and let, at the same time, a point, p, so 
move in that line, as ta describe the given 
curve, A C G : also let mm, or C », express 
Aa $ 
