. Teacher's manual for freehand drawing in intermediate schools. the point of a pencil is called a line ; but this hasbreadth, and so does not conform to the scientificdefinition. Lines are right or straight, as 1 ; curved, as 2 ;and broken, as 3. Straightlines are horizontal, oblique,or vertical. Curved lines arecircular, elliptical, &c. Linesare said to be continuous, as1 and 2 ; or discontinuous, as4. Two lines are said to beparallel, when they lie sideby side, and have the samedirection ; as 1 and 1, 2 and 2. They are, therefore,at the same distance apart throughout their wholelength. It w
. Teacher's manual for freehand drawing in intermediate schools. the point of a pencil is called a line ; but this hasbreadth, and so does not conform to the scientificdefinition. Lines are right or straight, as 1 ; curved, as 2 ;and broken, as 3. Straightlines are horizontal, oblique,or vertical. Curved lines arecircular, elliptical, &c. Linesare said to be continuous, as1 and 2 ; or discontinuous, as4. Two lines are said to beparallel, when they lie sideby side, and have the samedirection ; as 1 and 1, 2 and 2. They are, therefore,at the same distance apart throughout their wholelength. It will be seen that a broken line consistsof a series of lines, united, but having differentdirections. Surface. — Space enclosed by lines is called sur-face: it has, therefore, length and breadth, but 38 TEACHERS MANUAL. Think of a line as moving sidewise, and its pathwill form a surface. Illustrate b} using a piece ofwire, straight or curved, to represent a line ; mov-ing it sidewise through the air. The surface maybe a plane, to all parts of which a straight rule canbe applied exactl}; or it may be concave, that like the inside of a bowl; or convex, that is,bulofinof like the outside of a bowl or ball. With a rectangular piece of stiff paper, or card-board, 3ou can illustrate the three definitions whichhave been given. The angles, or corners, where theedges meet, will represent points; the edges them-selves will represent lines; and the surface of thepaper will show what is meant b} Sk plane. A Solid. — Space enclosed by surfaces is called asolid: it has length, breadth^ and thickness. Observe that the word ^ solid, as thus defined, hasno reference whatever to hardness, as it has in pop-ular usage, but only to magnitude, volume, varieties of the sol
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectdrawing, bookyear1876
