Arthur Rigg

“ Axes are tools to be used with both hands; they have long handles, and may be swung as sledge-hammers. Hatchets are to be used with one hand, have short handles, they are much lighter and thinner than axes, and are employed more in the trimming than in the hewing of timber. Both narrow and broad axes are employed in forestry, the woodman's choice being affected by the size of the timber and the character of the fibre. A hatchet is handled with the centre of gravity nearer the cutting-edge than the line of the handle; an axe with the centre of gravity in the line of handle produced. ”

“ When we pass from the tool and its contrived handle to the mode of using, and the purpose for which it has been constructed, we find, as a rule, a cutting-edge formed by two inclined surfaces meeting at an angle, the bisecting line of which passes through the middle of the metal. It is very apparent that the more acute this angle is, the greater, under the same impact, will be the penetrative power of the axe into the material against which it is driven. ”

“ A first class will comprehend tools which meeting the work at a particular angle continue the path of each portion of the edge in the same straight line. Axes, adzes, gouges, chisels, and planes (as ordinarily used by carpenters) , belong to this class. Such tools are brought into action either by impact or by direct thrust. The adaptation of machinery to tools in this class is easy, because the cutting-edge has to describe only a straight line, and this done once, if the place of application be removed, a repetition of impact or thrust in the same direction will suffice. ”

“ If the almost unconscious motions of a workman skilled in the use of an axe be observed, it will be noticed that, while the hand farthest from the axe-head grasps the handle at the same or nearly the same part, the other hand, or the one nearest to the head, frequently moves. ”

“ Now, although in any given case the work in a hammer consequent on its mass and velocity may be very great, yet utilizing the whole of the work produced in the expenditure of the accumulated power in the hammer depends upon the resistance met with at the instant of impact. The more perfect this resistance is, the greater will be the value of the work done ”

“ And as the contrast of the effect of the same tool under different circumstances in the same substance is considerable, great also is likely to be the contrast between the edges of the tools and the manner of using them, e. g., the axe, which is the proper tool in the direction of the fibre, is operated upon by impact, while a saw, which is the proper tool across the fibre, is operated upon by tension or thrust, but never by impact. ”

“ Let any one attempt to drive a nail vertically into an horizontal piece of timber by the statical effect of the simple pressure of a load placed gently on the head, as weights are laid in scale-pans. Let the depth to which the nail is thus moved be measured. Again, let the same nail, under the same circumstances, be driven to the same depth by the impact of a hammer-head, then it may for our present purpose be said that the load placed on the nail is a representative statical measure of the impact of the hammer. ”

“ By a varied mass there is a varied weight in the hammer; by a varied length of handle there will, with the same muscular effort, be a varied velocity in this mass, and upon a combination of mass and velocity depends the produced energy. Now, if a mass of metal, moving at a known velocity, strike an object, the energy of that blow results entirely from the conditions at the moment of impact. For example, the work in the hammer, H, as it strikes the nail, N (Fig. 20) , does not depend upon its velocity through the arc ”

“ The axes and adzes hitherto considered have been chiefly regarded as tools for the greatest amount of heavy work to be accomplished by a workman. They are at one extreme of the scale, the other extreme being the removal of such small flakes as to become shavings of varying thickness. In progressing from great to small, the order would be from the axe or adze with its weighted head to a separation of the cutting-edge and its necessary metal, and the weight which must give the blow. ”

“ In some handicrafts, and those too involving a high class of finished work, the hammer is the only tool employed. That great artistic skill in the use of the hammer as a finishing-tool can be acquired, is manifest from the many beautiful specimens of répoussé work to be seen in silversmiths' shops. ”

“ If any one has ever struck a common hatchet to any great depth into timber, and carelessly endeavored to loosen it by raising the extremity of the handle, he may have found the handle separate from the metal near the junction of the two. ”

“ The equally-inclined sides of the wedge-form of edge hitherto alone described as belonging to axes, and the equal pressure this form necessarily exerts upon each side if a blow is given in the plane of the axe, suggest what will be the action of an axe if the angle of the wedge is not bisected by the middle line of the metal. ”

“ The plane, in its most simple form, consists of a chisel inserted at an angle into a box, generally of wood, and with the cutting edge of the chisel projecting through the bottom of the box. If the actions of a workman be noted as he is smoothing wood with a chisel alone, it will be seen that he holds the bevel edge on the wood, and so elevates or lowers the handle as to secure a proper and efficient cut. Then he advances the tool in a line at right angles to its cross-section. ”

“ This instrument is raised by both hands until nearly in an horizontal position, and then not simply allowed to fall, but steadily driven downward until the curved metal, with its broad and sharp edge, enters near to, if not below, the sole of the workman's shoe, separating a large flake of wood from the mass; the handle is rapidly raised, and the blows repeated. This is done with frequency, the workman gradually receding his foot until the end-flakes of wood are separated. It is fearful to contemplate an error of judgment or an unsteady blow. ”

“ When, now, we pass from this light to very heavy work, it will be obvious that to hold a stone in the hollow of the hand, and to strike an object with it so that the reaction of the blow shall be mainly met by the muscular action of the back of the hand, and the thinnest section of the wrist, would be not only fatiguing, but might be injurious to the delicate network of muscles there found, and so damage this part of the hand. ”

“ When operated upon by hand alone, if an obstacle to the progress of the tool is presented, as, for instance, a twist or curl in the fibre or grain of the plank—the presence of a knot—then the workman by hand can adjust the handle, and so vary the inclination of the cutting edge as the circumstances of the case require. ”

“ We may intensify the blow, but we cannot, except just experimentally, and for the purpose of display, bring the restraining power of the muscles to diminish the energy of the descending hammer.—Journal of the Society of Arts. ”

“ The front of the sole of the box will clearly prevent the penetration of the incased chisel into the wood, because it cannot now be drawn to follow the fibre, should it lead inward. Suppose, however, that in the progress of the work such a place has been reached as would have so drawn the chisel inward. What will happen? Either the strength of the indrawing fibre will be so great that the workman will be unable to propel the tool, or, if not thus impeded, he must by extra effort separate the fibre and so release the tool. ”

“ In India it is held so near the metal that the workman's hand touches the metal. He accomplishes blows chiefly by acting from the elbow. This very general mode of holding gives a pretty uniform length to the radius of the swing, hence the form of the adze in the plane of the swing is nearly that of the circle described. The angle of the handle and the adze is very much the same as that of the handle of the file-maker's hammer and the head. ”

“ The mechanician has therefore to consider how to defeat these tendencies, which, as now sketched, result from a collision between the indrawing strength of the fibre and the power of the man to crosscut the fibre by the tool, or else to tear it asunder and leave the surface rough. ”

“ It will be noticed that the long handle of the adze is curved—the object of this is to permit an efficient blow to be given, and the instrument brought to a stop before the handle strikes any part of the workman's body; in fact, caused to stop by the exhaustion of its impact energy in and among the fibres of wood to be separated. The edge is often so keen as to cut through a horse-hair held at one end and pressed against it. ”

“ If the blow be given in the direction of the fibre, resistance to entrance of the edge is much less than in the blow across that fibre. So great, indeed, may this difference become, that while the axe in Class 1 seems in all respects a suitable tool, yet as the attention of the workman passes to directions inclined to the fibre at an angle of more than forty-five degrees, he will be induced to lay aside the tools in Class 1, and try those in Class 2 ”

“ Placed here so that the plane of intended cleavage shall be vertical when the wooden anvil is in the lead block, a deep scratch is made by a second diamond, in which scratch the edge of the splitter's chisel is to be planted. The diamond-splitter's chisel is very like an old razor. This chisel the workman holds in his left hand, in his right he holds that which is his hammer. The hammer is a plain steel rod, about eight inches in length, and tapering from about half an inch diameter in the middle to three-quarters of an inch at the end. ”

“ There is, however, one peculiarity, and that worthy of consideration. These bronze hatchets have in many instances a semicircular, ring-like projection (see Figs. 4 and 5) , the object of which was for a long time a puzzle, but the suggested mode of handling the implements, if correct as seen in the diagram, points to a knowledge of directions of tension and of pressure, which engineers at the present day cannot but admire. ”

“ Among the contrivances which have come down to us from the ages before history was written, or the use of metals known, are found stones shaped, as we may suppose, by the action of water, and so rounded as to lit the hand. ”

“ Assume that one face only is inclined, and that the plane of the other is continuous to the edge, then let the blow be struck as before. It will be obvious that the plane in the line of the fibres cannot cause any separation of these fibres, but the slope entering the wood will separate the fibres on its own side. Suppose a hatchet sharpened as previously described, and one as now described, are to be applied to the same work—viz., the cutting from a solid block the outside ”

“ Although thus abated, the cause is not removed, and even if so far abated as to prove no real impediment to the workman, yet the quantity of material removed on each occasion will be so small that the tool becomes one for finishing work only, and not for those various operations to which its present powers enable artisans to apply it. ”

“ Although externally alike except in size, they are yet used for different purposes, and each has a specialty met with in its construction. These specialties may now be considered.
After the wood has passed from the sawyer into the hands of the carpenter, the surface undergoes those operations which render it true and smooth. ”

“ If the defective construction is slight, then the work is often marked with angular indents. Arrangements, too, may be required for modifying the intensity of the blow, while retaining the effects resulting from a heavy hammer where a light one would be inefficient. ”

“ If its action passes below the bottoms of the furrows, then occasion arises for cutting the side-connection of the fibres, and, however a workman may sharpen the edge of his trying-plane for this purpose, he in one respect has destroyed one object of the plane, because, so soon as the iron penetrates below the surface, so soon does the effect of the jack-action begin to reappear, and the cutting edge should pass from the shape shown in Fig. ”

“ Since the tool, as now contrived, cannot efficiently cross-cut the resisting fibre, and since that fibre has to be removed, the object must be either to prevent such an accumulation of fibres as will stop the progress of the tool, or to destroy the fibre piecemeal as it is operative for hinderance. ”

“ CUTTING edges are sometimes doubled, and thus the chisel passes into another group of tools shears. The most common of these is the ordinary household scissors opened and closed by hand; when required for heavier work, then one handle is fixed in a . ”

“ A herd of cattle attacked by lions. S. Sheep at pasture, and their folds. 9. A dance. 10. The great ocean-river encompassing the whole, as, in the mind of Homer, it encompassed the earth. For examples of the use of hammers in the production of works of great variety and extent on a large scale, see the ancient hammered wrought-iron gates, hinges, and panels, in the architectural room in the South Kensington Museum ”