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114
IX. THE CAPITAL.
CONSTRUCTION.
a
9
Let, then, the quantity e d, and angle d b c, at A of Fig.
XXIII., be invariable, and let the length d b vary : then we
shall have such a series of forms as may be represented by
a, b, c, Fig. XXIV., of which a is a proportion for a colossal
building, b for a moderately sized building, while c could only
be admitted on a very small scale indeed.
§ xvi. 3. The greater the excess of abacus, the steeper must
be the slope of the bell, the shaft diameter being constant.
This will evidently follow from the considerations in the
last paragraph; supposing only that, instead of the scale of
shaft and capital varying together, the scale of the capital varies
alone. For it will then still be true, that, if the projection of
Fig. xxv. the capital be just safe on a given scale,
as its excess over the shaft diameter
increases, the projection will be unsafe,
if the slope of the bell remain constant.
But it may be rendered safe by making
this slope steeper, and so increasing its
supporting power.
Thus let the capital a, Fig. XXV,
be just safe. Then the capital b, in
which the slope is the same but the
excess greater, is unsafe. But the capital c, in which, though the excess equals
that of b, the steepness of the supporting slope is increased, will be as safe as
b, and probably as strong as a*
. xvn. 4. The steeper the slope of the bell, the thinner may
be the abacus.
The use of the abacus is eminently to equalise the pressure
over the surface of the bell, so that the weight may not by
any accident be directed exclusively upon its edges. In proportion to the strength of these edges, this function of the
abacus is superseded, and these edges are strong in proportion
* In this case the weight borne is supposed to increase as the abacus
widens; the illustration would have been clearer if I had assumed the
breadth of abacus to be constant, and that of the shaft to vary.
| Title | The stones of Venice - 1 |
| Creator | Ruskin, John |
| Publisher | J. Wiley |
| Place of Publication | New York |
| Date | 1889 |
| Language | eng |
| Type | Books/Pamphlets |
| Title | 00000139 |
| Type | Books/Pamphlets |
| Transcript | 114 IX. THE CAPITAL. CONSTRUCTION. a 9 Let, then, the quantity e d, and angle d b c, at A of Fig. XXIII., be invariable, and let the length d b vary : then we shall have such a series of forms as may be represented by a, b, c, Fig. XXIV., of which a is a proportion for a colossal building, b for a moderately sized building, while c could only be admitted on a very small scale indeed. § xvi. 3. The greater the excess of abacus, the steeper must be the slope of the bell, the shaft diameter being constant. This will evidently follow from the considerations in the last paragraph; supposing only that, instead of the scale of shaft and capital varying together, the scale of the capital varies alone. For it will then still be true, that, if the projection of Fig. xxv. the capital be just safe on a given scale, as its excess over the shaft diameter increases, the projection will be unsafe, if the slope of the bell remain constant. But it may be rendered safe by making this slope steeper, and so increasing its supporting power. Thus let the capital a, Fig. XXV, be just safe. Then the capital b, in which the slope is the same but the excess greater, is unsafe. But the capital c, in which, though the excess equals that of b, the steepness of the supporting slope is increased, will be as safe as b, and probably as strong as a* . xvn. 4. The steeper the slope of the bell, the thinner may be the abacus. The use of the abacus is eminently to equalise the pressure over the surface of the bell, so that the weight may not by any accident be directed exclusively upon its edges. In proportion to the strength of these edges, this function of the abacus is superseded, and these edges are strong in proportion * In this case the weight borne is supposed to increase as the abacus widens; the illustration would have been clearer if I had assumed the breadth of abacus to be constant, and that of the shaft to vary. |
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