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and Deposits of every description, pp. 170 to 246; Photography, pp. 246 to 295; Inks, pp. 343 to 349; Silvering, pp. 206 and 335; Gilding, pp. 188 to 199; Solders, p. 364; Soap, pp. 372 to 386; Candles, p. 350; Veneering, pp. 411 to 414; Marble Working, pp. 386 to 393; Dyeing, Graining, and Staining Wood, pp. 414 to 426; interspersed with other matters far too numerous to mention.
As far as possible subjects at all allied in character, either in constitution or mode of working, have been grouped together; and in general, the main subject is indicated by a heading in bold clarendon type, branch-subjects by small capitals, and details by italics. The difficulty, however, of obtaining certain information just when it was wanted, has prevented the adoption of anything like an alphabetical or other concatenated arrangement of the subject matter; it is believed that no inconvenience will arise from this cause, as the index is very comprehensive.
Care has been exercised in cases where the practical operation connected with a receipt has been apart from the writer's experience, to have it verified by authority, and the aim throughout has been to render 'Workshop Eeceipts' a reliable handbook for all interested in Technological pursuits.
ERNEST SPON. Augcst 1, 1873.
Drawing Paper.—The following table contains the dimensions of every description of English drawing-paper. inches. inches.
Demy 20 by 15
Medium .. .. 22 „ 17
Koyal 24 „ 19
Imperial .. .. 31 „ 21
Atlas 33 „ 2G
Double Elephant .. 40 „ 26
Emperor .. .. G8 „ 48
For making detail drawings an inferior paper is used, termed Cartridge; this answers for line drawings, but it will not take colours or tints perfectly. Continuous cartridge paper is also much used for full-sized mechanical details, and some other purposes. It is made uniformly 53 inches wide, and may be had of any length by the yard, up to 300 yards.
For plans of considerable size, mounted paper is used, or the drawings are afterwards occasionally mounted on canvas or linen.
Mounting Drawings or Paper on Linen.—The linen or calico is first stretched by tacking it tightly on a frame or board. It is then thoroughly coated with strong size, and left until nearly dry. The sheet of paper to be mounted requires to be well covered with paste; this will be best if done twice, leaving the first coat about ten minutes to soak into the paper. After applying the second coat, place the paper on the linen and dab it all over with a clean cloth. Cut off when thoroughly dry.
To Fasten Paper on a Drawing Board.—The stretched irregular edges of the sheet of paper are cut off against a flat ruler, squaring it at the same time. The sheet of paper is laid upon the board the reverse side upwards
to that upon which the drawing is to be made. It is then damped over, first by passing a moist clean sponge, or wide brush, round the edges of the paper about an inch and a half on, and afterwards thoroughly damping the whole surface, except the edges. Other plans of damping answer equally well; it is only necessary to observe that the edges of the paper should not be quite so damp as the other part of the surface. After the paper is thoroughly damped, it is left until the wet gloss entirely disappears; it is then turned over and put in its position on the board. About half an inch of the edge of the paper is then turned up against a flat ruler, and a glue-brush with hot glue passed between the turned-up edge and the board; the ruler is then drawn over the glued edge and pressed along. If upon removing the ruler the paper is found not to be thoroughly close, a paper-knife or similar article passed over it will secure perfect contact. The next adjoining edge must be treated in like manner, and so on each consecutive edge, until all be secured. The contraction of the paper in drying should leave the surface quite flat and solid.
Cutting Pencils.—If the point is intended for sketching, it is cut equally from all sides, to produce a perfectly acute cone. If this be used for Hue drawing, the tip will be easily brokeu, or otherwise it soon wears thick; thus, it is much better for line irawing to have a thin flat point. The general manner of proceeding is, first, to cut the pencil, from two sides only, with a long slope, so as to produce a kind of chisel-end, and afterwards to cut the other sides away only sitllicient to be able to round the first edge a little. A point cut in the manner described may be kept in good order for some time by pointing the lead upon a small piece of fine sandstone or fine glar.s-paper; this will be less trouble than the continual application of the knife, which is always liable to jreak the extreme edge.
Erasing Errors.—To erase Cumberland-lead pencil marks, native or bottle india-rubber answers perfectly. This, howaver, will not entirely erase any kind of German or other manufactured pencil marks. What is found best for this purpose is fine vulcanized india-rubber; this, besides being a more powerful eraser, has also the quality of keeping clean, as it frets away with the friction of rubbing, and presents a continually renewed surface to the drawing; the worn-off'particles produce a kind of dust, easily swept away. Vulcanized rubber is also extremely useful for cleaning off drawings, as it will remove any ordinary stain.
For erasing ink lines, the point of a penknife or erasing knife is commonly used. A much better means is to employ a piece of fine glass-paper, folded several times, until it presents a round edge; this leaves the surface of the paper iu much better order to draw upon than it is left from knife erasures. Fine size applied with a brush will be found convenient to prevent colour running.
To produce finished drawings, it is necessary that no portion should be erased, otherwise the colour applied will be unequal in tone; thus, when highly-finished mechanical drawings are required, it is usual to draw an original and to copy it, as mistakes are almost certain to occur in delineating any new machine. Where sufficient time cannot be given to draw and copy, a very good way is to take the surface off the paper with fine glass-paper before commencing the drawing; if this be done, the colour will flow equally over any erasure it may be necessary to make afterwards.
Where ink lines are a little over the intended mark, and it is difficult to erase them without disfiguring other portions of the drawing, a little Chinese white or flake-white, m^xed rather dry, may be applied with a fine sable-brush; this will render a small delect much less perceptible than by erasure.
Whenever the surface of the paper is roughened by using the erasing knife, it should be rubbed down with some hard and perfectly clean rounded instrument.
Buying' Drawing Instruments.—Persons with limited means will find it better to procure good instruments separately of any respectable maker, W. Stanley of Holborn for instance, as they may be able to afford them, than to purchase a complete set of inferior instruments in a case. With an idea of economy, some will purchase second-hand instruments, which generally leads to disappointment, from the fact that inferior instruments are manufactured upon a large scale purposely to be sold as second-hand to purchasers, principally from the country, who are frequently both unacquainted with the Workmanship of the instruments and of the system practised.
Inferior instruments will never wear satisfactorily, whereas those well made improve by use, and attain a peculiar working smoothness. The extra cost or purchasing the case and the nearly useless rules, would, in many instances, be equal to the difference between a good and an inferior set of instruments without the case. Instruments may be carefully preserved by merely rolling them up in a piece of wash leather, leaving space between them that they may not rub each other; or, what is better, having some loops sewn on the leather to slip each instrument separately under.
Drawing Board.—The qualities a good drawing board should possess are, an equal surface, which should be slightly rounded from the edges to the centre, in order that the drawing paper when stretched upon it may present a solid surface; and that the edges should be perfectly straight, and at right angles to each other.
In Using a Drawing Pen, it should be held very nearly upright, between the thumb and first and second fingers, the knuckles being bent, so that it may be held at right angles with the length of the hand. The bundle should incline only a very little —say ten degrees. No ink should be used except indian ink, rubbed up fresh every day upon a clean palette. Liquid ink and other similar preparations are generally failures. The ink should be moderately thick, so that the pen when slightly shaken will retain it a fifth of an inch up the nibs. The pen is supplied by breathing between the nibs before immersion in the ink, or by means of a small camel-hair brush; the nibs will afterwards require to be wiped, to prevent the ink going upon the edge of the instrument to be drawn against. The edge used to direct the pen should in no instance be of less than a sixteenth of an inch in thickness; a fourteenth of an inch is perhaps the best. If the edge be very thin, it is almost impossible to prevent the ink escaping upon it, with the great risk of its getting on to the drawing. Before putting the pen away, it should be carefully wiped-between the nibs by drawing a piece of folded paper through them until they are dry and clean.
To Test the Accuracy of a Straight-edge.—Lay the straightedge upon a stretched sheet of paper, placing weights upon it to hold it firmly; then draw a line against the edge with a needle in a holder, or a very fine hard pencil, held constantly vertical, or at one angle to the paper, being careful to use as slight pressure as possible. If the straight-edge be then turned over to the reverse side of the line, and a second line be produced in a similar manner to the first at about the twentieth of an inch distance from it, any inequalities in the edge will appear by the differences of the distances in various parts of the lines, which may be measured by spring dividers.
Another method will be found to answer well if three straight-edges are at hand; this method is used in making the straight-edge. Two straight-edges are laid together upon a flat surface, and the meeting edges examined to see if they touch in all parts, reversing them in every possible way. If these
two appear perfect, a third straightedge is applied to each of the edges already tested, and if that touch it in all parts the edges are all perfect. It may be observed that the first two examined, although they touch perfectly, may be regular curves; but if so, the third edge applied will detect the curvature.
In Using- the Plain Parallel Rule, one of the rules is pressed down firmly with the fingers, while the other is moved by the centre stud to the distances at which parallel lines are required. Should the bars not extend a sufficient distance for a required parallel line, one rule is held firmly, and the other shifted, alternately, until the distance is reached.
Using Dividers or Compasses.—It is considered best to place the forefinger upon the head, and to move the legs with the second finger and thumb. In dividing distances into equal parts, it is best to hold the dividers as much as possible by the head joint, after they are set to the required dimensions; as by touching the legs they are liable to change, if the joint moves softly as it should. In dividing a line, it is better to move the dividers alternately above and below the line from each point of division, than to roll them over continually in one direction, as it saves the shifting of the fingers on the head of the dividers. In taking off distances with dividers, it is always better, first to open them a little too wide, and afterwards close them to the point required, than set them by opening.
Pencilling.—If a drawing could be at once placed to the best advantage on the paper, and surely made without mistake and with all its lines correctly limited when first drawn, it might be made in ink directly on the blank paper. To avoid the errors inevitable in the first copy of any production, even when made by those most practised, drawings are first pencilled and then inked. The whole theory of pencilling, then, is, to lay out correct tracks on which the pen is to move, leaving the iniml, during the inking, free from all thought of accuracy of the construction, that it may be given to excellence in execution. Therefore, the whole of the pencil-construction should be most accurately made in the finest faint lines with a hard pencil.
Finishing a Drawing. — While "Finish a drawing without any error or defect," should be the draughtsman's best motto, he should never be in haste to reject a damaged drawing, but should exercise his ingenuity to see how far injuries done to it may be remedied. * Never lose a drawing once bcgun," should be his second motto; and since prevention is easier and better than cure, let him always work calmly, inspect all instruments, hands, and sleeves, that may touch a drawing, before commencing an operation; let the paper, instruments, and person be kept clean, and when considerable time is to be spent upon a portion of the paper, let the remainder be covered with waste paper, pasted to one edge of the board.
For the final cleaning of the drawing, stale bread, or the old-fashioned black india-rubber, if not sticky, is good; but, aside from the carelessness of ever allowing a drawing to get very dirty, any fine drawing will be injured, more or less, by any means of removing a considerable quantity of dirt from it.
Another excellent means of preventing injuries, which should be adopted when the drawing is worked upon only at intervals, is to enclose the board, when not in use, in a bag of enamelled cloth or other fine material.
Lettering.—The title to a drawing should answer distinctly the four questions— What, Who, Where, and When—What, including the use and scale; Who, both as to designer or inventor, and draughtsman; Where, both as to the place, institution, or office where the drawing was made, and the locality of the object drawn; and When.
If the drawing is perfectly symmetrical, its title should have the same axis of symmetry as the drawing. If the drawing is unsymmetrica., the title may be at either of the lower corners.
These principles do not apply to horizontal views, as maps of surveys, where the title may be wherever the shape of the plot affords the best place.
One quite essential element of beauty in a title is its arrangement, or the form of its outline as a whole. It should embrace such variations in the length of its lines of letters that the curve formed by joining the extremities of those lines would be a simple and graceful one, having also a marked variety of form. Also the greatest length of the title should generally be horizontal; or its proportions, as a whole, like those of the border of the drawing.
When the occupation of the paper affords only narrow blank spaces lying lengthwise of the paper, the title looks well mostly on a single line at the bottom, the principal words being in the middle, and the subordinate ones at the two sides.
Moreover, horizontal lines should prevail in the direction of the lines of words in the title. Indeed, the title may be arranged wholly on horizontal lines with good effect, though an arched or bow-shaped curve for the principal words may be adopted when the drawing includes some conspicuous arching lines.
The size of the title should be appmpriate to that of the drawing. In particular, the rule has been proposed that the height of the largest letters in the title should not exceed three-hundredths of the shorter side of the border. Also, the relative size of the different portions of the title should correspond to their relative importance, the name ot the object and its inventor being largest, and that of the draughtsman, his location, and the date of his work being considerably smaller.
Geometrical drawings are most appropriately lettered with geometrical letters, which, when neatly made, always look well. Any letters, however, having any kind of sharply-defined and precise form, as German text, are not inappropriate to a geometrical drawing •, but vagiely formed " rustic" or other