[Ill.u.s.tration: PLATE IX.]
And the height of the wood at the middle bout is five-eighths of an inch; at the upper seven-sixteenths of an inch; at the lower, bare half-inch more or less, a fine eye being necessary to discriminate to a hair.
CHAPTER VI.
WORKING OUT THE BACK.
Pa.s.sing on, I draw your attention to the working out of the back.
I show you, fig. 10, what must be drawn on the back and belly (on the flat, of course) before a chisel touches the wood for excavation. The blocks at either end speak for themselves, they having been fashioned to shape out of Swiss pine, and planed and squared so as to be glued square where you see them marked, later on. And be sure they stand one-and-a-half inches high in the rough, for a reason I will give you later, and about five-eighths of an inch thick, to about the breadth you see on fig. 10.
[Ill.u.s.tration: PLATE X.]
Before, however, you can do anything in hollowing out the back, you will have to provide yourselves with a bed in which your table must firmly rest while you do so. Therefore, purchase a block of dry beech or birch, about one-and-a-half inches thick, sixteen inches long by eleven inches wide, and lay your finished back in the centre of it, tracing the whole outline, b.u.t.ton as well, distinctly thereon; and having done so, cut by the outline inside all round to the depth of about one quarter of an inch, and from this basis proceed to make, as nearly as possible, a counterpart of the model of your back, but reversed, of course. And get all the tool ridges well levelled with rough to fine sandpaper; and, when you lay in your table for cutting, place a strong piece of brown paper for it to rest upon, not only to prevent it in any way scratching the fine surface of your wood obtained at so much trouble, but it enables you to shake off it quickly any residue of coa.r.s.e dust or small cuttings that _will_ creep under the wood upon which you are working; and so you get on rapidly and cleanly.
You will notice that I have again drawn the guitar line, and at a distance from the outline, so that a sufficiently flat surface is allowed for the ribs to rest firmly upon later. And I cut all round this line just as an indication, merely as a starting point from which to work more deeply all over, until I arrive at a point when the calipers, No. 34, test the thicknesses roughly--which is by the way. For I have first to cut three cross channels, at the upper, middle, and lower nodal points, fig. 11, at such a depth that I caliper good three-sixteenths of an inch at the centre of middle groove, one-eighth of an inch upper and lower, falling away very little to all edges for the present. And I draw a distinct pencil mark through each groove, so that I must be a poor workman indeed if I go through the wood through these bars, as I have known some novices to do, or cannot gauge pretty well all over by their aid before using the calipers.
[Ill.u.s.tration: PLATE XI.]
But you who, when beginning to cut out back or belly, having no sort of experience whatever, must use every care possible, and keep calipers No. 3 (double) going constantly, as, with their aid, you will at once see by the outside half the thickness registered at the inner; then you can pare away with gouges, small and large, and with spoke shaves, Nos. 48 and 53, until you get a fairly sloping and somewhat level surface from bare three-sixteenths of an inch in centre to full three-thirty-seconds of an inch all round by the edges, as shown by calipers.
And thus I come to the first rough thicknesses of the back; and I damp the surface all over as I did the outside, and dry it carefully; for you will understand the necessity for this carefulness, there being some fear of slight warping from the true flatness now the wood is thin all over, if quick, artificial heat be adopted to draw the moisture.
Whilst this natural process is going on, you must take the large calipers and open them at three-sixteenths of an inch. Then hold the plate in the extended left hand by middle bout, inside upwards, calipers and a long lead pencil _together_ in the other; and, beginning at the centre of the plate, draw the calipers carefully from this starting-point all over the rough surface, gauging with your eye for the present any irregularities of said surface; for I want you to mark every part where the points stick, first within a radius of three inches, gradually extending your field of operations, slightly tightening the calipers as you get farther away from your centre, until the edges are finally reached, when you use the double calipers, No. 3, to ascertain the exact thickness at those places.
This being done, and the places marked levelled down, using spoke shaves, flat gouge No. 50, and rough sandpaper 3, take again the large calipers and go over the whole as before, but more carefully; and do this time after time, until the plate is accurately gauged from five-thirty-seconds of an inch centre to the diminution of about a good sixteenth--say one-twelfth of an inch at the edges. My way of working has always been thus, in preference to using what people call "indicating calipers"; and my advice to you is, do likewise, for you not only get over your ground more nimbly, but you can get from your centre more accurately, I maintain, gradation of thicknesses. I give you what I have proved the best thicknesses for my backs, and am pleased to do so to all the world; but if you care to try a hair or two thinner in the centre, adding those hairs to the edges, do so; you will not lose in energy, but you will in timbre, a trifle.
Before finally quitting this hollowing out of the back, gauge for the last time, then use fine sandpaper, and leave no mark of any tool whatever, as by clean work you will be judged.
This question of thicknesses is an important one, but applies more to the belly than the back; and I shall have more to say on this head when I get to that soundboard, merely adding now that the back must never be weak in wood, yet, at the same time, never so strong that a woody tone is the result, inevitable, as the timbre quality is scarcely developed, and without that I never care for it.
It is desirable at this stage that I point out to you how the inner edges of the back are rounded before the ribs are fixed. I use file No. 6, half round, flat side to the wood first, turning to the round side for finish. When at the corners, I employ knife No. 8 in cutting where the file would not do it so well in the early stage, and this file not at all nicely for finish, so I employ a smaller one, No. 9, to these corners, the other all over the rest of the wood, cleanly doing the work so that about one-sixteenth only of the inner edge is rounded off. Then No. 1 sandpaper is used to finish off the work done, and the next stage is glueing on the end blocks, preparatory to fixing the ribs as they get made--of which, later.
So, for the present, I leave the back, and take up the wood you will remember I selected for the front table, or belly, and devote to it a separate section; merely adding that in the course of my work I have so arranged all the thicknesses of the back that it answers to the tone C, which do not forget, as I shall have again to refer to it.
CHAPTER VII.
THE BELLY.
This is the soundboard of the instrument--that which, I suppose, vibrates as fourteen to ten as compared with the back--that is to say, it is recorded that, given equal conditions, such will be the case. It is that which first receives concussion as the bow strikes the strings, which shock travels down the upper surface of the gut from the bridge until the nut at the end of the fingerboard be reached, when it flies under the said string to the bridge again, which communicates the shock to the belly, the belly to the back by soundpost, ribs, neck, scroll, and all about it, to the ma.s.s of air in the body of the violin, when comes what we call tone, and rightly do we call it so, if pure vibrations have been brought into play, otherwise noise would be a much safer word to use. Of course, I give you the above in detail: it will appear to you as though the whole of the agitations were simultaneous, such is the amazing rapidity with which all this takes place. And I only give it to show you how inc.u.mbent it is upon you to use every care in all you do when engaged in this work, more especially that on the upper table. For no matter how well your back may be gauged, finished, and finally adjusted; or your ribs, how equally balanced one with another or in relative proportions with the whole: if your tell-tale soundboard be defectively wrought, cheeks too much hollowed, or the thicknesses carelessly seen to, there will be beats in your tone, strings irregular, weak notes and strong ones, and a general unsatisfactory result which could easily have been avoided.
But I will get to work on this upper table; and, there being some interesting features to notice as the panorama of its construction pa.s.ses before your eyes, you will do well to let nothing escape your observation; besides, there is much that is merely a repet.i.tion of the working of the back, and which I omit in letterpress.
The said back, you will remember, was in a whole piece--this belly is in two pieces, as I intimated under the heading "selection of wood"; and, as a natural consequence, has to be joined before I can operate upon it as a whole before you. The manner of preparing the two half plates for a joint is this:--upon this bench I place what is called a shooting board--a board, as you may observe, upon which, near one end, is inserted, right across it from edge to edge, a piece of wood, square with the length, to serve as a stop against which I press what it will be convenient to call one half of the roof of a house, fig. 1, plate 12, lengthwise, which serves to ill.u.s.trate one half of the belly, thickest edge, of course, on a square with the edge running along by where rests a very choice trying plane, on its side, tool touching this plate, which I hold with my left hand firmly, whilst I _shoot_ the said plane from end to end of the half belly, fig. 2, plate 12. This I repeat on the other half, and then hold them together, flat side towards me, as I raise the two to a strong light, and if no glimmer whatever creeps between the joint, then I call the two plates perfectly united, and ready for the glue to make this absolute. But if they do not appear as I intimate, then you must operate until this very important part of your work be strictly that of a perfect whole; for, remember, as a whole the two parts must remain for as long as the violin holds together, which may be for two hundred years over and above the years that shall be given to you who make it; and this alone should be an incentive to good work.
[Ill.u.s.tration: PLATE XII.]
We now arrive at this joining of the wood for the soundboard, and the glue to be used must be of the best. Not too thin, but sufficiently so to drop freely from the brush used, and clear whilst being tenacious, as felt by pressure between finger and thumb.
As you may observe, I place one half of the wood in the vice of the bench, and on this, the other half (fig. 3, plate 12). With the hot glue to my right hand, I take the loose half of the wood in my left, and hold it against the one fixed in the bench, and upon the two broad centres or outside edges thus exposed, I work rapidly a good layer of the glue, and then, placing them on each other again, I move them very firmly backwards and forwards, and so they are united, remaining in the bench until set.
My dear friends, it is not to be supposed you will do this exceedingly difficult piece of business even moderately well at first; but you will have to do it somehow as a commencement, and I hope I have made all clear to you. Think the thing well over; see your way well ahead; and I am quite sure your success will be commensurate with your endeavour.
From this stage you will have to repeat what was done to the back, until you reach the cutting out of the groove preparatory to insertion of the purfling; and I only stop you here to direct your special attention to one feature of that groove, or, rather, four of the same character, viz., the corners. These, owing to the soft nature of the wood, will be difficult for you to cut out clean, so as to leave the sharp point (so much admired when well done, so much condemned when ill) clear and distinct; and you must use small sharp knife, No. 8, to effect this, not taking the gouge, 52, to the extreme corner when using it near to it, as the pressure would, without doubt, break it off.
Leaving you with this caution, I shall imagine all done as was the work on the back up to cutting the groove after purfling, plate 6, and resume there, for the purpose of warning you that the gouges for this same work on the soft pine, as opposed to the sycamore, must be exceptionally sharp, and you _must cut_, and very clean, too, or you will tear the wood, and go below your level, as I before cautioned you. More than this I need not say just here, so proceed with the modelling of the belly, on the former lines gone over for the development of the back, with this difference, you must only use coa.r.s.e sandpaper in the very early stages, and continue the work over more stages by at least three than on the back; for pine takes more readily scratches, and takes them deeper, than sycamore; and more patience in bringing it to a surface like satin, where no trace of scratch from sc.r.a.per or sandpaper can be detected under delicate varnish.
Then you must continue until the finished plate 9 is reached, only, as I said above, bringing up the surface to a finer state than the back--not to be called waste of time by you on any account, as you will soon understand when you come to find out what a heartless exposer of any frailty is oil varnish.
So at length we come to the hollowing out and to the thicknesses of the belly.
CHAPTER VIII.
THICKNESSES OF THE BELLY.
Cut the three channels across as explained for the back, but in this way:--At the upper nodal point, so that your calipers register bare one-eighth of an inch from one side to the other, centre as well--same at the other node; and at the centre, full--rather over--one-eighth across, all to be for the present only, as a slight correction will be effected as the final stage of the use of the calipers is reached.
Then operate over the whole surface on these lines, taking little or nothing from the extreme edges, because I want you to reserve your strength there in case your pine turns out very active--that is to say, very sensitive to vibration, in which case, mark me, you must keep up your strength of wood, as this extreme activity will not be in harmony with the regulation ma.s.s of air in the violin, and the steadiness of tone will suffer in consequence.
And, that you may very clearly understand the reason of this occasional activity, I must tell you that sometimes the wood, in being cut by the saw at the mill, gets a trifle _off the quarter_ on to the slab; and this, coming to the edges, is less able to withstand the strength of the air in its action of 512 beats to the second, say of responsive C; whereas, all being properly and fairly on the quarter, a slight diminution is allowed, and I consider necessary. And I think the above remarks will very fully explain _why_ we so insist on the upper table being _never_ on the slab or near it.
So we will consider the wood roughened out as I directed, and now I must get you to follow me closely whilst I arrange the thicknesses so that I get that tone which I have found the fullest, the most rich in quality, and of the finest carrying power.
I work at the part of the belly which I call the centre, as it is the place where the bridge stands and answers to central node, consequently the middle of the whole construction and of the ma.s.s of air: I sc.r.a.pe and level here until I get a fraction, a hair or two less than one-eighth of an inch thick. This I continue along the breast until I arrive at both upper and lower nodal crossings, when I gradually thin off to both ends, the final thickness being at the flat left for the end block when the belly is attached to it, one-thirty-second of an inch less than the centre. And I reduce from the centre of the breast to half-way towards all four edges, top and bottom, about as at the centre, barely, and to the edges, till they register a fraction thinner than at the upper and lower ends.
The above, be it understood, is when finally finished and smoothed down. I now show you with the calipers how accurately the work corresponds with the theory advanced; and on this, my favoured mode of working for the tone so highly spoken of by my numerous admirers, I have no more to say, except to tell you that the wood so finished corresponds in tone to D, and you will still remember that the back was C.
But other thicknesses than these, both of back and belly, are employed; such as thinner in back and thicker in belly; and as used by Joseph Guarnerius del Jesu--the back about such as we have used in this instrument, but the belly a trifle THINNER in the centre than at the edges--they being about one-eighth of an inch. And we have it on record that many of the violins of Stradivari were originally _one thickness_ all over the upper table, barely one-eighth, and about as I use for the lower; would that we could speak with authority on this as on many another point! But many instruments have had wood taken from them by vampires and faddists, and we can _not_ speak with authority as to the vital points of scores of these n.o.ble efforts of art, therefore better not lay down laws or adduce supposed facts regarding them, but do our utmost to build up something as n.o.ble, and each one of us leave art no worse than he found it, casting reproach and scorn on the utterly indifferent, or the detestable pander or the vampire.
As I have not to recur to the thicknesses again, it may here be a convenient place in which to say a few words on the nodal points in relation thereto.
Many of you may not know what a "node" in music means exactly--some of you may know nothing whatever about it. Simply, it is the fixed point of a sonorous chord, at which it divides itself, when it vibrates by aliquot parts, and produces the harmonic sounds. And do you not see how this struck chord can serve and does serve to ill.u.s.trate my exposition of the back and belly--more particularly the latter--in their vibrations and their concentration at upper, middle, and lower nodes? To these places they fly, they cling, singly, thin, and of no character; and from these places they again fly, but united in a strong, sonorous _tone_. How then, think you, will fare those worked out cheeks or attenuated edges, (some of which latter I have seen no thicker than a worn shilling), when worked hard and in a hot room? Gentlemen, they will sound like something between a musette and a Jew"s harp, when you are near to the player; they will not be heard _at all_ some yards away! Yet it is such a tone (!) which many hundreds of old violins possess, and after which so many million people run. Please note this is entirely without prejudice. Every person has a perfect right to use his own judgment; and tastes differ.
CHAPTER IX.
THE SOUNDHOLES.