PART I.--THE ESSENTIAL ELEMENTS.

SECTION I.--THE DRAWING OFFICE AND ITS FURNISHINGS.

PAGE

The Drawing Office 1 Instruments 2 Materials 5 Precautions and Remarks 9

SECTION II.--GEOMETRICAL PROBLEMS. 15

SECTION III.--LINES, DOTS, AND THEIR COMBINATIONS.

Straight and Curved Lines 27 Lines of uneven thickness 30 The Broken Line 30 The Dotted Line 31 Combinations of Straight, Broken, and Dotted Lines 31 The Wavy Line 33 Grass-land 34 Swamps and Marshy Ground 35 Sand and Gravel 35 Woodland 36 Uncultivated Land 37 Contour Lines 37

SECTION IV.--COLOURS.

Flat-tints 40 Conventional Colours 44 Water 45 Grass-land 45 Marsh 45 Sand and Gravel 46 Mud 46 Woodland 46 Cultivated Land 47 Uncultivated Land 47 Buildings 47 Roads and Streets 47 Fences 47

SECTION V.--SHADING.

Application of Shade Lines 48 Cylindrical Surfaces 50 Shading Lines 50 Shading Lines on Cylindrical Surfaces 51 Shading Lines in Topographical Drawings 52 The Vertical System of Shading 57 Shading in Colours 63 Hill Slopes 63 Cylindrical Surfaces in Mechanical Drawings 64