give the abbreviated method commonly used by technical draughtsmen.
Freehand Drawing and Sketching.—This term implies drawing or sketching in which the hand of the worker is " free " in the sense of not being guided or restricted in its action by any mechanical means such as squares, compasses or rulers.
The result depends upon the skill or practice of the sketc.her. It is an acquirement worth cultivating, as often a graphic sketch made in a few seconds will illustrate one's meaning much more readily than a laborious verbal description. In Chapter IX. will be found a few hints and devices that the author has found of assistance in his own practice.
Practical Geometry.—Geometry is defined as that branch of mathematics which treats of the measurements of lines, surfaces and solids, with their various relations ; and practical geometry is the method of applying its principles to the requirements of trades or handicraft.
Almost all mechanical drawing is based on geometrical principles, and in the chapter which is devoted to this subject a selection of examples is given in which it is shown how these well-established principles may be utilised in solving the everyday problems of the workshop .and drawing office.
Working Drawings.—The term, working drawing, is commonly used by architects to indicate those drawings which they supply to builders as part ot the necessary directions for doing the wrork. These drawings vary in scale from | in. to the foot, or even smaller, up to full size, according to convenience or necessity. Further working drawings are generally made from these, for the direct use of the workman; these are, in carpenters' and joiners' work particularly, practically always full size, and are generally made (or set out, as it is termed) by the foreman or a specially efficient workman termed a " setter-out." These full-size drawings are usuallv made upon prepared boards termed
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