Encyclopaedia Britannica, or, a Dictionary of arts, sciences, and miscellaneous literature : enlarged and improved. Illustrated with nearly six hundred engravings > Volume 5, BUR-CHI

'CAN
Canon, form a canon of this kind, it is only neceffary for the
^ compofer to make an air according to his tafte ; to add
in fcore as many parts as he choofes, where the voices
in oitave or uniform repeat the fame melody j then
forming a tingle air from all thefe parts fucceflively ex¬
ecuted, to try whether this fucceflion may form an en¬
tire piece, which will give pleafure as well in the har¬
mony as the melody.
In order to execute fuch a canon, he who lings the
firft part begins alone, and continues till the air is fi-
nilhed •, then recommences immediately, without any
fufpenfe of found or interruption of time j as foon as
he has ended the firft couplet, which ought to ferve
for the perpetual fubje£t upon which the whole canon
has been compofed, the fecond part begins and repeats
the fame couplet, whilft the firft who had begun pur-
fues the fecond : others in fucceflion begin and pro¬
ceed the fame way, as foon as he who precedes has
reached the end of the frit couplet. Thus, by incef-
fantly recommencing, an univerfal clofe can never be
found, and the canon may be repeated as long as the
lingers pleafe.
A perpetual fugue may likewife confift of parts
which begin with the intervals of a fourth or fifth ; or,
in other words, every part may repeat the melody of
the firft, a fourth or a fifth higher or lower.. It is
then necelfary that the whole canon fliould be invent¬
ed di prvna intenxione, as the Italians fay ; and that
lharps or flats Ihould be added to the notes, whofe na¬
tural gradations do not anfwer exactly, by a fourth or
fifth, to the melody of the preceding part, and pro¬
duce the fame intervals with itfelf. Here the compo¬
fer cannot pay the leaft regard to modulation 5 his on¬
ly care is, that the melody may be the fame, which
renders the formation of a canon more difficult j for at
wvery time when any part refumes the fugue, it takes
a new key •, it changes the tone almoft at every note,
and, what is ftill worfe, no part is at the fame time
found in the fame tone with another j hence it is that
this kind of canons, in other refpedts far from being
eafy to be perufed, never produce a pleafing efteft,
however good the harmony may be, and however pro¬
perly it may be fung.
There is a third kind of canon, but very fcarce, as
well becaufe it is extremely difficult, as becaufe it is for
the moft part incapable of giving pleafure, and can
boaft no other merit but the pains which have been
thrown away in its compofition. This may be called
a double canon inverted, as well by the inverfions which
are praftifed in it wuth refpeft to the melody of the
parts, as by thofe which are found among the ,parts
themfelves in finging. There is fuch an artifice in
this kind of canon, that, whether the parts be fung in
their natural order, or whether the paper in which
they are fet be turned the contrary way, to fing them
backward from the end to the beginning, in fuch a
manner that the bafs becomes the upper part, and the
reft undergo a fimilar change, ftill you have pretty har¬
mony, and ftill a regular canon. The reader may con-
fult Roulfeau’s Dictionary in this article, where he is
referred to Plate D. fig. ti. for two examples of ca¬
nons of this fort extra£ted from Bonterapi, who like-
wife gives rules for their compofition. But he adds,
that the true principle from which this rule is deduced
will be found at the word Syjleme, in his account of
CAN
the fyftem ofTartini, to which we muft likewdfe once
more refer the reader •, as a quotation of fuch length
muft have protracted our article to an enormous ex¬
tent.
To form a canon, in which the harmony may be a
little varied, it is neceflary that the parts fliould not
follow each other in a fucceflion too rapid, and that
the one ffiould only begin a confiderable time after the
other. When they follow one another fo immediately
as at the diftance of a femibreve or a minim, the dura¬
tion is not fufficient to admit a great number of chords,
and the canon muft of neceffity exhibit a difagreeable
monotony 5 but it is a method of compofing, without
much difficulty, a canon in as many parts as the com¬
pofer cheofes. For a canon ef four bars only, will
confift of eight parts, if they follow each other at the
diftance of half a bar •, and by each bar which is add¬
ed, two parts will eonftantly be gained.
The emperor Charles VI. who was a great mufieian,
and compofed extremely well, took much pleafure in
compofing and finging canons. Italy is ftill replete with
moft beautiful canons compofed for this prince, by the
belt mafters in that country. To what has been fiiid
by Rouffeau, we need only fubjoin, that the Englilh
catch and the Italian canon are much the fame j as any
intelligent reader may perceive, from comparing the
ftrudlure and execution of the Engliffi catch with the
account of canons which has now been given.
Canon, in Geometry and Algebra, a general rule
for the folution of all cafes of a like nature with the
prefent inquiry. Thus every laft ftep of an equation
is a canon •, and, if turned into words, becomes a rule
to folve all queftions of the fame nature with that pro-
pofed.
CANON Law, a collection of ecclefiaftical laws,
ferving as the rule and meafure of church-govern¬
ment.
The power of making laws was exercifed by the
church before the Roman empire became Chriftian.
The canon law that obtained throughout the weft, till
the 12th century, was the collection of canons made
by Dionyfius Exiguusin 520, the capitularies of Char¬
lemagne, and the decrees of the popes from Sircius to
Anaftafius.
The canon law, even when papal authority was at
its height in England, was of no force when it was
found to contradict the prerogative of the king, the
laws, ftatutes, and cuftoms of the realm, or the doctrine
of the eftabliffied church.
The ecclefiaftical jurifdiction of the fee of Rome in
England was founded on the canon law j and this
created quarrels between kings and feveral archbifhops
and prelates who adhered to the papal ufurpation.
Befides the foreign canons, there were feveral laws
and conftitutions made here for the government of the
church : but all thefe received their force from the
royal aflent j and if, at any time, the ecclefiaftical
courts did, by their fentence, endeavour to enforce
obedience to fuch canons, the courts at common law,
upon complaints made, would grant prohibition. The
authority veiled in the church of England of making
canons, was afeertained 'by a ftatute of Henry VIII.
commonly called the aB of the clergy's fubmi/Jion ; by
which they acknowledged, that the convocation had
always been affembled by the king’s writ j fo that,
S 2 though
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