1the Sweep of the Fillet at Bottom; and in this
terminate all the Diameters that are in the
Thickneſs of the Shaſt, and it does not run
ſtrait like the Axis, but is compoſed of a great
Number of Lines, ſome ſtrait and ſome curve;
as we ſhall ſhew hereafter. The ſeveral Dia
meters of Circles which we are to conſider in
different Parts of the Column, are ſive; the
Sweeps, the Diminutions, and the Swell or Belly
of the Shaft. The Sweeps are two, one at the
Top and the other at the Bottom of the Co
lumn, and are called Sweeps upon account of
their running out a little beyond the Reſt of
the Shaft, The Diminutions are likewiſe two,
cloſe by the Sweeps at the Bottom and Top,
and are ſo called becauſe in thoſe Parts the
Shaft diminiſhes inwards. The Diameter of
the Swell or Belly of the Column is to be ob
ſerved about the Middle of the Shaft, and is
called the Belly, becauſe the Column ſeems to
ſwell out juſt in that Part. Again, the Sweeps
differ from one another, for that which is at
the Bottom is formed by the Fillet and a ſmall
Curve running from the Fillet to the Body of
the Shaft; but the Sweep at the Top of the
Shaſt, beſides this Curve and its Fillet has like
wiſe the Aſtragal. Laſtly, the Out-lines muſt
be formed in the following Manner: On the
Pavement, or upon the flat Side of a Wall,
which is proper for the Drawing your Deſign,
draw a ſtrait Line, of the Length which you
intend to give the Column, which perhaps is
as yet in the Quarry. This Line we call the
Axis of the Shaft. Then divide this Axis into
a certain Number of determinate Parts, ac
cording to the Nature of the Building, and of
the various Sorts of Columns which you are to
erect, of which Variety we ſhall ſpeak in due
Time; and according to a due Proportion of
theſe Parts you muſt make the Diameter of the
Bottom of your Shaft, with a little Line drawn
acroſs the Axis. The Diameter you divide in
to four-and-twenty Parts, one of which you
give to the Height of the Fillet, which Height
we mark upon the Wall with a ſmall Stroke;
then take three more of thoſe Parts, and at
that Height make a Mark in the Axis of the
Shaft, which is to be the Center of the next
Diminution, and through this Center draw a
Line exactly parallel with the Diameter of the
Bottom of the Shaft, which Line muſt be the
Diameter of the lower Diminution, and be one
ſeventh Part ſhorter than the Diameter of the
Bottom of the Shaft. Having marked theſe
two Lines, that is to ſay, the Diameter of the
Diminution, and the Fillet, draw from the
Point of the End of the Fillet to the Point of
that Diameter in the Shaft of the Column a
curve Line, as eaſy and neat as poſſible; the
Beginning of this curve Line muſt be one Quar
ter of a little Circle, the Semi-diameter of
which muſt be the Height of the Fillet. Then
divide the whole Length of the Shaft into ſeven
equal Parts, and mark thoſe Diviſions with lit
tle Dots. At the fourth Dot, counting from
the Bottom, make the Center of the Belly of
the Shaft, acroſs which draw its Diameter,
whoſe Length muſt be equal to the Diameter
of the Diminution at the Bottom. The Di
minution and Sweep at the Top muſt be made
as follows: According to the Species of the
Column, of which we ſhall treat elſewhere,
take the Diameter of the upper Superficies from
the Diameter of the Bottom of the Shaft, and
draw it at the Top of the Column in your De
ſign; which Diameter ſo drawn muſt be di
vided into twelve Parts, one of which Parts
muſt be allowed to the Projecture of the Fillet
and Aſtragal, giving two thirds of it to the
latter, and one third to the former. Then
make the Center of your Diminution, at the
Diſtance of one and a half of thoſe Parts from
the Center of the upper Surface of the Shaft,
and the Diameter of this Diminution a ninth
Part leſs than the largeſt Diameter of that Sur
face. You muſt afterwards draw the Curve or
Sweep in the ſame Manner as I taught you to
draw that below. Laſtly, having thus marked
in your Deſign the Sweeps, Diminutions, and
all the other Particulars which we have here
mentioned, draw a ſtrait Line from the Dimi
nution at the Top, and another from the Di
minution at the Bottom to the Diameter of the
Belly or Swell of the Column, and this will
make in your Deſign what we called the Out
line of the Column, and by this Line you may
make a Model of Wood by which your Ma
ſons may ſhape and finiſh the Column itſelf.
The Superficies of the Bottom of the Shaft, if
the Column be exactly rounded, muſt make
equal Angles on all Sides with the Axis in the
Middle, and with the like Superficies at the Top
of the Shaft. Theſe Things I do not find com
mitted to writing by any of the Ancients, but I
have gathered them by my own Induſtry and
Application from the Works of the beſt Ma
ſters. All that is to follow may be for the
moſt Part referred to the Proportions of the
Lines already treated of, and will be very de
lightful and of great Uſe, eſpecially to the Im
provement of Painters.
terminate all the Diameters that are in the
Thickneſs of the Shaſt, and it does not run
ſtrait like the Axis, but is compoſed of a great
Number of Lines, ſome ſtrait and ſome curve;
as we ſhall ſhew hereafter. The ſeveral Dia
meters of Circles which we are to conſider in
different Parts of the Column, are ſive; the
Sweeps, the Diminutions, and the Swell or Belly
of the Shaft. The Sweeps are two, one at the
Top and the other at the Bottom of the Co
lumn, and are called Sweeps upon account of
their running out a little beyond the Reſt of
the Shaft, The Diminutions are likewiſe two,
cloſe by the Sweeps at the Bottom and Top,
and are ſo called becauſe in thoſe Parts the
Shaft diminiſhes inwards. The Diameter of
the Swell or Belly of the Column is to be ob
ſerved about the Middle of the Shaft, and is
called the Belly, becauſe the Column ſeems to
ſwell out juſt in that Part. Again, the Sweeps
differ from one another, for that which is at
the Bottom is formed by the Fillet and a ſmall
Curve running from the Fillet to the Body of
the Shaft; but the Sweep at the Top of the
Shaſt, beſides this Curve and its Fillet has like
wiſe the Aſtragal. Laſtly, the Out-lines muſt
be formed in the following Manner: On the
Pavement, or upon the flat Side of a Wall,
which is proper for the Drawing your Deſign,
draw a ſtrait Line, of the Length which you
intend to give the Column, which perhaps is
as yet in the Quarry. This Line we call the
Axis of the Shaft. Then divide this Axis into
a certain Number of determinate Parts, ac
cording to the Nature of the Building, and of
the various Sorts of Columns which you are to
erect, of which Variety we ſhall ſpeak in due
Time; and according to a due Proportion of
theſe Parts you muſt make the Diameter of the
Bottom of your Shaft, with a little Line drawn
acroſs the Axis. The Diameter you divide in
to four-and-twenty Parts, one of which you
give to the Height of the Fillet, which Height
we mark upon the Wall with a ſmall Stroke;
then take three more of thoſe Parts, and at
that Height make a Mark in the Axis of the
Shaft, which is to be the Center of the next
Diminution, and through this Center draw a
Line exactly parallel with the Diameter of the
Bottom of the Shaft, which Line muſt be the
Diameter of the lower Diminution, and be one
ſeventh Part ſhorter than the Diameter of the
Bottom of the Shaft. Having marked theſe
two Lines, that is to ſay, the Diameter of the
Diminution, and the Fillet, draw from the
Point of the End of the Fillet to the Point of
that Diameter in the Shaft of the Column a
curve Line, as eaſy and neat as poſſible; the
Beginning of this curve Line muſt be one Quar
ter of a little Circle, the Semi-diameter of
which muſt be the Height of the Fillet. Then
divide the whole Length of the Shaft into ſeven
equal Parts, and mark thoſe Diviſions with lit
tle Dots. At the fourth Dot, counting from
the Bottom, make the Center of the Belly of
the Shaft, acroſs which draw its Diameter,
whoſe Length muſt be equal to the Diameter
of the Diminution at the Bottom. The Di
minution and Sweep at the Top muſt be made
as follows: According to the Species of the
Column, of which we ſhall treat elſewhere,
take the Diameter of the upper Superficies from
the Diameter of the Bottom of the Shaft, and
draw it at the Top of the Column in your De
ſign; which Diameter ſo drawn muſt be di
vided into twelve Parts, one of which Parts
muſt be allowed to the Projecture of the Fillet
and Aſtragal, giving two thirds of it to the
latter, and one third to the former. Then
make the Center of your Diminution, at the
Diſtance of one and a half of thoſe Parts from
the Center of the upper Surface of the Shaft,
and the Diameter of this Diminution a ninth
Part leſs than the largeſt Diameter of that Sur
face. You muſt afterwards draw the Curve or
Sweep in the ſame Manner as I taught you to
draw that below. Laſtly, having thus marked
in your Deſign the Sweeps, Diminutions, and
all the other Particulars which we have here
mentioned, draw a ſtrait Line from the Dimi
nution at the Top, and another from the Di
minution at the Bottom to the Diameter of the
Belly or Swell of the Column, and this will
make in your Deſign what we called the Out
line of the Column, and by this Line you may
make a Model of Wood by which your Ma
ſons may ſhape and finiſh the Column itſelf.
The Superficies of the Bottom of the Shaft, if
the Column be exactly rounded, muſt make
equal Angles on all Sides with the Axis in the
Middle, and with the like Superficies at the Top
of the Shaft. Theſe Things I do not find com
mitted to writing by any of the Ancients, but I
have gathered them by my own Induſtry and
Application from the Works of the beſt Ma
ſters. All that is to follow may be for the
moſt Part referred to the Proportions of the
Lines already treated of, and will be very de
lightful and of great Uſe, eſpecially to the Im
provement of Painters.
*
The End of Book
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