Technical drawing

“ But unless your eye is exactly opposite the hub of the wheel in the line of the axle, the wheel does not make a circle on the retina of your eye, and ought not to be represented by a circle in your drawing. To draw well, the first resolution and the first duty is to see well. Second, do not suppose that mere technical method has much to do with real success. Soft pencil rather than hard; sepia rather than India ink. It is pure truth that tells in drawing, and that is what you can gain. ”

“ Whatever the name may be,—Collotype, Artotype, Albertype, Phototype, or Carbon-gravure,—the principle is the same; an impression is made in printer's ink from a photo-chemically produced design on a gelatine surface, either on the hand-press or on a power cylinder press similar to that used in lithographic printing.
There is hardly any process which is more capable of producing fine works of art. It is the only true method for reproducing, in the full sense of the word, an etching, engraving, a drawing in pen and ink, an aquarelle, a painting, or objects from nature. ”

“ Mechanical drawings are seldom tinted, but are mainly produced in India ink. Where, however, a fine effect is desired, working drawings are colored, so as to show at a glance the material of which the different parts are to be made. ”

“ Drawings that are to be intricate, or to contain a great many lines, as a drawing of an engine or of a machine, are best pasted or glued all around the edges of the paper, which should first be dampened; but as the learner will scarcely require to make such drawings until he is somewhat familiar with and well practised in the use of the instruments, this part of the subject need not be treated here. ”

“ One artist makes it a thick line with a blunt pen, another a thin line with a fine pen, and another, like Moullier, makes it with a series of dots, but each of these methods is a matter of technic, and the rules of technic are arbitrary, not fixed as are the rules for drawing. You may invent your own technic, but you cannot invent perspective. ”

“ Stretching or pasting the paper to the board is very seldom resorted to, for the reason that the mechanical drawings are to scale and the paper is natural when pinned to the board and more correct than if under a strain. Mechanical drawings are always required in practice right away, and time would be wasted and lost in damping and pasting and drying again.
A working drawing, whether made to a scale or not, must have all the dimensions plainly written upon it, for a workman should never be compelled to measure a drawing. ”

“ It is sometimes found necessary to prepare a highly finished and shaded drawing of the work in hand. Such elaborations, in fact, are much admired by the uninitiated, although the complete shading of the drawing is no criterion as to the scientific value of the machine. ”

“ The lines in sectional shading or cross-hatching may be made to denote the material of which the [82] piece is to be composed. Thus Professor Unwin has proposed the system shown in the Figures 95 and 96. This may be of service in some cases, but it would involve very much more labor than it is worth in ordinary machine shop drawings, except in the case of cast iron and wood, these two being shown in the simplest and the usual manner. It is much better to write the name of the material beneath the piece in a detail drawing. ”

“ It is now generally recognised that the old-fashioned method of teaching machine drawing is very unsatisfactory. In teaching by this method an undimensioned scale drawing, often of a very elaborate description, is placed before the student, who is required to copy it. Very often the student succeeds in making a good copy of the drawing placed before him without learning very much about the object represented by it, and this state of matters is sometimes not much improved by the presence of the teacher, who is often simply an art master, knowing nothing about machine design. ”

“ It is the numerous inquiries from working machinists for a book of this kind that have led the author to its production, which he hopes and believes will meet the want thus indicated, giving to the learner a sufficiently practical knowledge of mechanical drawing to enable him to proceed further by copying such drawings as he may be able to obtain, or by the aid of some of the more expensive and elaborate books already published on the subject. ”

“ WE WISH to supplement the preceding pages with a chapter on the technic of wood engraving, and a few words about kindred arts which are of special consequence to the illustrator-printer. The art of wood engraving I consider one of the most valuable things for the illustrator-printer to learn. True, this art is going out of use because of its tediousness; and, it must be confessed, if you wish a picture of a building in your paper, it is much more economical and you can get a better result if you make a pen drawing and send it to be photo-engraved, than if you engrave it on wood. ”

“ To prepare a drawing that will be in every way suitable for reproduction usually requires experience of a kind not acquired in many other kinds of drafting, such as preparing engineers' or architects' drawings, because the drawings themselves or blue prints made directly from them are the things the engineer or the architect desires. Drawings prepared for reproduction are generally made larger than publication size, and it is therefore necessary to gage each line, letter, or feature for a definite reduction. ”

“ This description of drawing is applicable to wood engraving, to line engraving upon copper or steel, as well as to all the methods for automatically producing blocks for relief printing. The line method is also universally adopted by etchers in intaglio.
Successfully to prepare drawings for photographic reproduction it is essential that some knowledge should be possessed of the fundamental principles of {95} photography, as well as an acquaintance with the capabilities of the particular process of production which is to be employed. ”

“ For the most efficient presentation of drawing there will need to be plenty of blueprints or plates from which the student may work. These must be so well executed, as to technique, that the pupil will have before him only the best as models. No one would think of placing before the writing class other than the best models of style and execution in penmanship, yet it is not infrequent to find mechanical drawing students copying from blueprints that are far below standard as to excellence. ”

“ The subscriber, being practically acquainted with all the various kinds of Drawing used, is able to represent Machinery, Inventions, or Designs of any kind, either by Authographic Drawing, or in Isometrical, Parallel, or True Perspective, at any angle best calculated to show the construction of the Machinery of Design patented. ”

“ It may be remarked that they only draw well who draw intelligently; aptness in this, as in many other virtues, is a matter of slow growth, “here a line and there a line”—it’s the proper direction, not the rate of progress, that counts in the end.
There are several methods of drawing—1, Free-hand; 2, Instrumental; 3, Geometrical; 4. Perspective. In the first the work, also termed sketching, is executed by pencil, pen, crayon, or even paint-brush; in the second the result is attained by the use of rule, tee-square, drawing pen, etc. ”

“ A further important requirement is that the drawing be sharply and cleanly worked, and since the reproduction of a ragged or broken line cannot make a full smooth beautifully running line, they will appear in the reproduction in the same defective way, and then require at least tedious retouching or make the printing of the subject actually impossible. If it is necessary to cross the lines in the shadows this must be done with great care. The points of crossing must be clean and sharp, and the ink must not run. ”

“ As the wood-engraver grew proficient in his technique, he widened his field by imitating the effect of etching or engraving on copper, in rivalry with this form of illustration. In this he succeeded so well that the other, more expensive modes of adornment were largely driven from the field of book illustration. With the advent of photography, the design could be fixed upon the wood block mechanically, accurately, without the trouble of a careful drawing. The values of tone in the photograph relieved the engraver from the work of translating color-values into black and white. ”

“ Even in drawings made with full flowing brush or pen, there will be modulations in the strength of the ink, or occasioned by the surface of the wood or paper, in every stroke, by which the, sensitive artist in the heat of work cannot help being influenced, and which will lead him to give a bloom, a delicacy, to his drawing, such as a print can never possess. ”

“ They correspond to the sketches made by the engineer or draftsman for drafting-room or shop use. The experience of many instructors seems to indicate that the early introduction of freehand perspective and orthographic sketching in a course of mechanical drawing serves as a means of developing that skill in freehand execution which is so necessary in rendering the freehand features of a mechanical drawing. When this type of skill is acquired before the mechanical work is started, the mechanical and freehand technique may be simultaneously developed. ”

“ I cannot over-emphasize the importance of your realizing that you have been told sufficient about pen drawing for you to go ahead and make drawings for your paper. If there is anything more to be learned I am candid in saying that you are better able to find out what it is than I am, for it is almost entirely a matter of printing, and not of engraving. Photo-engravers can nowadays reproduce almost any kind of a drawing, but a cut which might print well in a magazine might not print at all in your country newspaper. ”

“ Mechanical drawings should be made with reference to all the processes that are required in the construction of the work, and the drawings should be responsible, not only for dimensions, but for adaptation to fitting, forging, pattern-making, moulding, and so on. ”

“ When we come to the analyzation of the human face this fact of representing parts of the body by lines that are not outlines—i. e., not contour lines—will be still clearer to you. Now, the point we want to make is that the method of “placing” objects, recommended in the last chapter, is not a mere process of procedure in drawing, but is quite as important a mental training as the making of the most intricate outline—in fact, for the printer-draftsman it is more important than the latter. ”

“ The ink does not take on the damp gummed stone, but only where the lithographic chalk has made a greasy mark, so that a perfect facsimile of the drawing on stone is obtained, when a sheet of paper is placed on the stone and the whole put through the press.
The medium deserves to be much more popular with draughtsmen than it is, as no more perfect means of reproduction could be devised. ”

“ A general view means a view showing the machine put together or assembled, while a detail drawing is one containing a detail, as a part of the machine or a single piece disconnected from the other parts of the whole machine.
It is obviously desirable in a mechanical drawing to present the piece of work in as few views as possible, but in all cases there must be a sufficient number to permit of the dimensions in every necessary direction to be marked on the drawing. ”

“ A mistake, sir. Both in type-founding and in stereotyping the Americans have driven the foreigner from the field,—and in the only legitimate way, too: simply by surpassing him.
In this nook below, our engraving is done. The drawing is made on the block by the designer, as you see: then patiently and skilfully the engraver cuts and digs out, till the lines and shapes and lights and shades are all revealed in the beautiful picture. Our work in this department gives so much satisfaction that we are seldom without orders. ”

“ Ordinarily we do not recommend to the printer to experiment with such effects, but rather to confine himself to outline or silhouette, but the value of the white-line will be considered in connection with wood engraving, and any practice in drawing from nature in light masses will help you appreciate the judicious use of white-line in wood engraving, or strong contrasts of white and black in any medium. ”

“ The same circle may be drawn over several times to make a thorough test. If a drawing instrument will draw a fine line correctly, it will be found to answer for thick lines which are more easily made.
In thus preparing the instruments, the operator will find that if he occasionally holds the points in the right position with regard to the light, he will be able to see plainly if the work is proceeding evenly and equally, for if one-half of the pen is thicker at the point or edge than the other, it will show a brighter line. ”

“ Either they propose to give the student a power of dexterous sketching with pencil or water-colour, so as to emulate (at considerable distance) the slighter work of our second-rate artists; or they propose to give him such accurate command of mathematical forms as may afterwards enable him to design rapidly and cheaply for manufactures. When drawing is taught as an accomplishment, the first is the aim usually proposed; while the second is the object kept chiefly in view at Marlborough House, and in the branch Government Schools of Design. ”