TRI 
TRI 
the ratio of on a footing -with tlie. quadrature of the cir- 
rd (8) diipli- cle, and the duplicature of the cube angle, 
iecond or of TRISPAST, in mechanics, a machine 
- UllL lilC llUCc iillici yiicis a»v« lit/u* uiooa* j 
ed for polishing metals, maibles, am o er rather longer and thinner than the 
minerals, and likewise for polishing glass, jg supposed to be a na- 
Formerly it was supposed to be a yolcainc of Tartary. The farmers 
production, which has been long since is- spring-wheat, because it will come 
proved, and it appears to be an extremely sickle with the common wheat, 
line mixture of clay and sand. though it should be sown in February or 
TRIPPANE, in mineralogy, is of an ap* March. T. hybernmn, winter or common 
pie-green, or greenish white. It occurs in ^-heat, has also four flowers in a calyx, 
mass, is moderately hard, and easily frangi- j|,ree of which are mostly productive. The 
ble. Specific gravity is 3.21. Before, the calyces stand on each side a smooth flat re* 
blow-pipe, it becomes yellow, and splits in- ceptacle, as in the former species, but they 
to thin plates, and then melts into a thin g,.g uot quite so far asunder. The leaves 
transparent glass. It has hitherto been jjjg calyx are bellying, and so smooth 
found in Sweden, in veins of quartz and ^ 1 , 3 ^ t[,gy appear as if polished, but they 
mica. have no arista. The glumes of the flowers 
TRIPPING, in heraldry, denotes the too are smooth, and tile outer ones, near 
quick motion of all sorts of deer, and of the top of the spike, are often tipped with 
some other creatures, represented with one short aristae. The grain is rather plumper 
foot as it were on a trot. than the former, and is the sort most gene- 
TRIPSACUM, in botany, a genus of the rally sown in England ; whence the name 
Monoecia Triandria class and order. Na- of common wheat. T. turgidnm, thick- 
tural order of Gramina, Gramine®, or spiked or cone-wheat, is easily distinguish- 
Grasses. Essential character : male, calyx ed from either of the former ; for though 
glume four-flowered ; corolla glume mem- it has four flowers in a calyx, after the 
branaceous; female, calyx glume with per- manner of them, yet the whole calyx, and 
forated sinuses ; corolla glume two-valved ; the edges of the glumes, are covered 
styles two ; seed one. There are two spe- with soft hairs. The calyces, too, stand 
cies, viz. T. dactyloides, and T. herma- thicker on the receptacle, and make the 
phrodituni. spike appear more turgid. Some of the 
TRISECTION, or Trissection, the outer glumes, near the top of the spike, are 
dividing a thing into three. The term is terminated by short arist®, like those of 
chiefly used in geometry, for the division of the common wheat. The grain is shot tei , 
an angle into three equal parts. The trisec- plumper, and more convex on the back 
tion of an angle geometrically, is one of those than either of the former species. Its va- 
great problems whose solution has been so rieties are numerous, and have various ap- 
much sought by mathematicians for these pellations in difterent counties, owing to 
two thousand years, being, in this resperf, the great affinity of several of them. 
