. Teacher's manual for freehand drawing in intermediate schools. ontal sections. No. 1 rep-resents what is seen when the toy-house whose frontelevation is given at 4, and end elevation at 5, iscut horizontally across through the middle of thelower windows. It shows the position of the door,windows, chimneys, stairway, kitchen, sitting-room,also the thickness of the walls and other parts. is a similar representation of a horizontal sectionthrough the middle of the upper ^^indows. The 94 TEA CHERS MAN UAL. stairway, it will be seen, is a winding one, the lowerhalf shown on plan 1, the upper
. Teacher's manual for freehand drawing in intermediate schools. ontal sections. No. 1 rep-resents what is seen when the toy-house whose frontelevation is given at 4, and end elevation at 5, iscut horizontally across through the middle of thelower windows. It shows the position of the door,windows, chimneys, stairway, kitchen, sitting-room,also the thickness of the walls and other parts. is a similar representation of a horizontal sectionthrough the middle of the upper ^^indows. The 94 TEA CHERS MAN UAL. stairway, it will be seen, is a winding one, the lowerhalf shown on plan 1, the upper half on plan 2. No. 3 is a plan of the roof and chimue3--tops, thedouble dotted lines indicating the walls of the house,which would not be seen by the e^e looking directhdown upon the house. No. 6 is an elevation of thehouse when viewed at an angle of 45° as representedin the plan, from which the elevation is points in the elevation are secured bymeans of the dotted lines drawn perpendicularlv up-wards from the same points in the plan. Observe. that the full length of the roof is shown by the lineah in the plan ; but. in the elevation, ah shows itforesJiortened, as it appears seen at an angle of 45^.Thus the foreshortened lines in the elevation can beobtained from the full line in the plan. BLACKBOARD LESSONS. 95 But observe that neither the plan nor the eleva-tion gives the full length of the line ^vhich repre-sents the width of the roof from the eaves to theridge-pole. But one who understands working-drawings can, by the aid of the two foreshortenedlines, ae and ae\ determine just the length of theactual line which the}- represent. Indeed, the truelength of any line, whatever its actual position, mayalways be obtained from its plan and elevation com-bined. On this simple fact, which enables one torepresent the exact proportions of anv object, reststhe whole vast superstructure of working-drawings,for machinery, building, and engineering purposes. Blackboard L
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectdrawing, bookyear1876
