Encyclopaedia Britannica, or, a Dictionary of arts, sciences, and miscellaneous literature : enlarged and improved. Illustrated with nearly six hundred engravings > Volume 6, CHI-Crystallization

c L E f 187 ] C L E
Clef. and a fourth from the F, or fa, which is found be-
-'^r“ neath the firft line, to the fi, or B, which is found
above the laft, and all this together forms what we call
the general clavianj ; from whence we may judge, that
this compafs has, for a long time, conftiluted the ex¬
tent of the fyftem. But as at prefent it is continually
acquiring new degrees, as well above as below, the de¬
grees are marked by larger lines, which are added above
or below as occafion requires.
Inftead of joining all the lines, as has been done by
Roufleau in his Diftionary, (plate A, fig. 5.) to mark
the relation which one clef bears to another, they fe-
parate them five by five ; becaufe it is pretty nearly
within the degrees to which the compafs of ordinary
voices extends. This collection of five lines is called a
fave; and in thefe they place a clef, to determine the
names of the notes, the poiitions of femitones, and to
(how what ftation the ftave occupies in the claviary or
general fcale.
In whatever manner we take five fucceflive lines in
the claviary, we fliall find one clef comprehended ; nay,
fometimes two, in which cafe one may be retrenched as
ufelefs. Cuftom has even prefcribed which of the two
fhould be retrenched, and which retained $ it is this
likewife which has determined the number of pofitions
affigned to each clef.
If I form a ftave of the firft five lines in the clavia¬
ry, beginning from below, I find the clef of fa in the
fourth line. This then is one pofition of the clef, and
this pofition evidently relates to the loweftnotej thus
likewife it is that of the bafe clef.
If I wifti to gain a third in afcent, I muft add a line
above ; I muft then obliterate one below, othervvife
the ftave will contain more than five lines. The clef of
fa then is found transferred from the fourth to the
third, and the clef of ut is likewife found upon the
fifth ; but as two clefs are ufelefs, they retrench here
that of ut. It is evident, that the ftave of this clef is
a third higher than the former.
By throwing away ftill one line below to gain ano¬
ther above, we have a third kind of a ftave, where the
clef of fa will be found upon the fecond line, and that
of ut upon the fourth. Here we leave out the clef of
fa, and retain that of ut. We have now gained ano¬
ther third above, and loft it below.
By continuing thefe alterations from line to line,
we pafs fucceflively through four different pofitions
of the clef of ut. Having arrived at that of fol, we
find it placed upon the fecond line, and then upon
the firft. This pofition includes the five higheft lines,
and gives the lharpeft diapafon which the clefs can fig-
nify.
The reader may fee in Roufleau’s Mufical Di&ion-
ary, Plate A, fig. 5. this fucceffion of clefs from the
loweft to the higheft ; which in all conftitutes eight
ftaves, clefs, or different pofitions of clefs.
Whatever might be the charaffer and genius of any
voice or inftrument, if its extent above or below does
not furpafs that of the general claviary, in this number
may be found a ftation and a clef fuitable to it •, and
there are, in reality, clefs determined for all the parts
in mufic. If the extent of a part is very confiderable,
fo that the number of lines neceflary to be added above
or below may become inconvenient, the clef is then
changed in the courfe of the mufic. It may be plainly
perceived by the figure, what clef it is neCeffary to clef
choofe, for raifing or depreffing any part, under what- H
ever clef it may be actually placed. Clematis.
It will likewife appear, that in order to adjuft one v
clef to another, both muft be compared by the gene¬
ral claviary, by means of which we may determinf*
what every note under one of the clefs is with re-
fpe£t to the other. It is by this exercife repeated
that we acquire the habit of reading with eafe all the
parts.
From this manoeuvre it follows, that we may place
whatever note we pleafe of the gamut upon any line
or fpace whatever of the ftave, fince we have the
choice of eight different poiitions, which is equal to the
number of notes in the o6tave. Thus you may mark
a whole tune upon the lame line, by changing the clef
at each gradation. The 7th fig. of the fame plate in
Roufleau’s Mufical Diftionary, to which we formerly
referred, ftiows by the feries of clefs the order of the
notes, re, fa, la, ut, mi, fol, f, re, rifing by thirds,
although all placed upon the fame line. The fig. fol¬
lowing reprefents upon the order of the fame clefs
the note ut, which appears to defcend by thirds upon
all the lines of the ftave.j and further, which yet, by
means of changing the clef, ftill preferves its unifon.
It is upon fuch examples as this, that fcholars ought
to exercife themfelves, in order to underftand at the
firft glance the powers of all the clefs, and their fimul-
taneous effefh
There are two of their pofitions, viz. the clef of
To/ upon the firft line, and that of fa upon the third,
which feem daily to fall more and more into defuetude.
The firft of thefe may feem lefs neceflary, becaufe
it produces nothing but a pofition entirely limilar to
that of/tf upon the fourth line, from which, however,
it differs by two o&aves. As to the clef of fa, it is
plain, that in removing it entirely from the third line,
we ftiall no longer have any equivalent pofition, and
that the' compolition of the claviary, which is at
prefent complete, will by thefe means become de-
fed! ive.
Thus much for Roufleau’s account of clefs. Fie pro¬
ceeds to explain their tranfpofition $ but as this woukl
render the prefent article too long and intricate, we
refer the curious to his Mufcal Diciionanj, vol. i.
page 162. See alfo Mai corn's Differ tation on Muffc.
CLEFT, in a general fenfe, is a fpace made by the
feparation of parts. Green timber is very apt to fplit
and cleave in feveral places, after it is wrought into
form j and thele cracks in it are very difagreeable to
the fight. The common method of the country car¬
penters is to fill up thefe cracks with a mixture of
greafe and faw duft j but the neateft way of all is,
the foaking both fides well with the fat of beef broth*
and then dipping pieces of fpunge into the fame broth*
and filling up all the cracks with them : they fwell
out fo as to fill the whole crack ; and accommodate
themfelves fo well to it, that the deficiency is hardly feen.
Clefts, or Cracks, in Farriery, appear on the bought
of the patterns, and are caufed by a {harp and malic,
nant humour. See Farriery Index.
CLEMA, in antiquity, a twig of the vine, which
ferves as a badge of the centurion’s office.
CLEMA I IS, Vjrgins’-bower. See Botany /«-
dext
CLEMENCY,
A a 2