The southern press. [volume] (Washington [D.C.]) 1850-1852, 1851-06-09
Mechanism, No. Nv.

lrlUOnOmetTy IS the science OF LTlQngle9 and
more an art than science. The term is de-
rived from three Greek words hi, three; gnnia
corner; and metron, measure. 1t hence literally,
means the measure of trangles; really and prac-
ti"ally measuring by trianges. So curious, USE
full, and wonderful are the properties Of TRAN
giles, as to constitute instruments and furnish
modes for measuring any body, however irregu-
lar, and whether of one, two, or three dimen-
sions--length, or length and breadth, or length,
breadth, and thickness They also furnish in
struments for measuring bodies, however dis
tanf, at least within the distance Of the sun, and
extended much beyond it. The heights of
mountains, the distances OF bodies across rivers,
and the dimension, Of them, or other interven-
ing objects at distance, well as those accessi-
BILE or near at hand. by the wonderful powers of
trianges can be determined with great accu-
racy and by very simple modes. Surveying, nav
igation, astronomy, engineering, architecture,
and even the squaring Of every building erected.
have trigonomety, or some one or more proper
ties of triangles. at their foundation.
Every tbree.s ded figure is called triangle
or tr1on, angulns being the Latir, and gonia
the Greek, of the word angle, or corner Three
sided figures of plain surfaces, and bounded by
straight lines, are called plain triangles When
ofcurved surfaces and bounded by curved lines,
tcN are Cdicu NutNVu TIA kiCs. vvbcu OOuHOcQ
By three great circles of sphere, rs the eaua-
tor, eclip,ic, and meridian of the EARTH three
sided figure is called ; spherical triangle, and
the science relating to that class Of triangles is
called spherical trigonometry; rs that 10 plain
trianges is called plain trigonometry. The
properties Of these two classes Of three-sided
figures are 40 different and distinct and each so
important both to science and art, as to consli-
tuie two separate sciences, and each important
If not essential to the other. 1toq
OF plain triangles there are six different kinds
three differing in their sides and three in their
angles When all the sides are equal, or Of the
same length any three-sded figure ia called an
euuilateral triangle. When two sides are equal,
and either longer or shorter than the third il is
called an sosceles triangle. When all the sides
are unequal, or of different lengths, it is called
scalcne triangle. Every plain Triangle having
one right angle as no one can have two is called
a right angle triangle. If one angle is obtuse
or larger than right angle, it is called an OBJ
tuse angle Triangle If all the nncles are acute,
or smaller (sharper) than right anglr, it is
oaled acute angle triangle. IF a triangle
have one right angle and two equal sides, IL is a
right anpled sosceles Triangle, combining the
properties both Of triangles and squares The
whole secret of the "Chintse Puzzles" is in the
smaller number Of pieces Of wood, paper, ivory,
porcelain, glass, or other material in the shape
of a right angled sosceles triangle, say one inch
for each Of the two equal sides, can be combined
into forms literally without number, illustrating
natural and artificial mechanism in forms ex-
ceedingly beautiful and curious and applicable,
both in scientific and business operations, to an
extent without limits.
Erper ments.--Let any teacher or parent give
to his pupils or children, AS a forenoon exercise,
IN excursion for examining and collecting min
erals or other objects Of nature coming under
their observation As an afternoon exercise let
them draw and describe upon their slntes or
upon paper, or both. the various objects thus
coming under their observation. If they should
find one mineral, and draw.a three sided figure,
they would SNAKE beginning" a. the work Of
one day. in a "Cahnet of Nature and Art" illus
trating agriculture and mechanism, and take the
first step towards preparing specimens for Gag
ricutural Fairs for which premiums are offered
by the Maryland Society, rs they doubtless will
be awarded by any society thus favor I'd by the
work Of young hands and generous minds.