SECTION XXIX.

Of Curve-lined Triangular Figures.

Mother. Nos. 1, 2, 3, 4, are curve-lined triangles.

The first is a concave angled,

the second a convex

angled triangle.

The third triangle has two mixed and one con

vex angle.

The fourth has one concave and two mixed angles.

Draw four concave-angled triangles. Draw three convex-angled triangles with interior angles-with exterior angles. Draw a triangle of one concave and two convex angles, &c.

With four lines compose four-sided figures, and see what sort of angles they have. To extend these exercises, the mother may draw figures of five, six, seven, eight, and nine angles; and ask the children how many, and what sort of angles each of these figures contains.

SECTION XXXI.

Of different sorts of Curves or arched Lines.

The mother draws the lines 1, 2, 3, saying, the first is called a waved line:

the second, an oval:

the third, a spiral line.

Mother. Can you draw a waved line? Draw an oval line: a spiral line.

APPLICATION.

Mother. Can you show me a curve or an arched line in this room? The brim of a hat:

the foot of that candlestick.

on the cups and saucers, &c.

I see round lines

Show me two

not parallel circular lines. Two parallel ones. Show me a concave angle. (The point of a knife generally forms such an angle.) Show me a convex angle. Try whether you can find, in the field or in the garden, leaves which have convex, concave, or mixed angles. Search today for leaves which form only concave angles. Try to find some of an oval form. The flower or the tree, of which the child has taken the leaves, may be named to him.

Look to-day for leaves of a triangular form; for such as form convex-angled triangles, &c.

Look for four, five, and six-angled figures. The mother now and then takes a plant, and asks the child how many, and what sort of angles its leaves have, &c.

Drawing Exercises in curve Lines, and Forms composed of them.

Mother. Invent some figure by a combination of parallel curve lines.

Produce a symmetrical form, by a combination of parallel and not parallel curve lines.

8

Draw one composed of curve-lined angles.

Another, by a combination of separate curvelined concave angles.

Produce one or two drawings of convex twoangled figures. Another of mixed two-angled figures, &c.

Invent a figure, by combining convex-angled triangles. Another,

by curve-lined paral

lel trapeziums.

Produce some pretty forms of curve-lined

pentagons, hexagons,

&c.

Another, by a combination of ovals. Draw a combination of spiral and of waved or serpentine lines.