o which you will have to devote great
attention: from the shadow thrown by the bar in fig. 15 you will
notice that it is shaped somewhat after a gracefully wrought bow,
unbent, and at once makes it apparent that it will be a factor for
good, as many such have I proved to be.

The reader must not consider the two blemishes on each upper curve
of the D as shown on fig. 15, errors in work; they are evidently
thumb marks, and dirty ones, through carelessness of photographer.

This brings us at length to the end of the construction of back and
belly, both of which we shall leave for the present, whilst we
consider the very essential ribs.

CHAPTER XI.
THE RIBS.

The thickness, but more especially the depth of these, is of much
consequence in relation to strength and quality of tone. I have
found a bare sixteenth of an inch answer very well for thickness,
and on the model I have worked on before you, in depth one and a
quarter of an inch at lower or broad end, gradually narrowing to one
and one-eighth full at the narrow.

Now, take the thickness for granted; but follow me very closely
while I describe to you how I arrive at the depth being just what I
want and sought for to obtain the note B _before_ the soundpost is
inserted, when you blow in the _f_, C, _after_ it is fixed. Of
course, this is making the scientific part of the work, or one of
them of no sort of anxiety to you, being already done by me at no
little trouble and much thought; but, as I set out as a teacher, if
only of moderate calibre, I shall go through with my endeavour to
make some good workmen out of my listeners and readers, therefore
you are welcome to what is, I think, of importance, never minding
what will be said at the outset, that all this fuss is somewhat of
nonsense, seeing that it was _so_ easy to copy the depth of a rib,
and get to what was wanted and avoid it. But I do not like copying
where I can help it; besides, what I shall lay before you has the
merit of getting at what you want to a nicety, and of finding out
what depth of rib will suit the model in hand, and obtaining the
mass of air of which I before spoke.

On a finished back, just like the one which we have before us, I
fitted a set of ribs about one inch deep to three-quarter inch
taper, and on a similar belly to this, another set of like depth;
but I so arranged that those on the back should be one thirty-second
more _out_ than usual--that is to say, nearer the edges