Alberti, Leone Battista, Architecture, 1755

Page concordance

< >
Scan Original
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
< >
page |< < of 320 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb xlink:href="003/01/055.jpg" pagenum="43"/>
              of this Line I ſix a Nail in the Ground, from
                <lb/>
              which I raiſe, and let fall Perpendiculars, ac­
                <lb/>
              cording to the Method of the Geometers; and
                <lb/>
              to theſe two Lines I reduce every Thing
                <lb/>
              that I have Occaſion to meaſure; which ſuc­
                <lb/>
              ceeds perſectly well in all Reſpects; for the
                <lb/>
              Parallel Lines are obvious; you ſee exactly
                <lb/>
              where to make your Angles correſpondent,
                <lb/>
              and to diſpoſe every Part conſiſtently, and
                <lb/>
              agreeably, with the others. </s>
              <s>But if it ſo hap­
                <lb/>
              pens, that any old Buildings obſtruct your
                <lb/>
              Sight from diſcovering and fixing upon the
                <lb/>
              exact Seat of every Angle; your Buſineſs
                <lb/>
              then is to draw Lines, at equal Diſtances, in
                <lb/>
              thoſe Places which are clear and free; then
                <lb/>
              having marked the Point of Interſection, by
                <lb/>
              the Aſſiſtance of the Diameter and Gnomon,
                <lb/>
              and by drawing other Lines at equal Diſtances,
                <lb/>
              fitted to the Square, we may compleatly effect
                <lb/>
              our Purpoſe: And it will be of no ſmall Con­
                <lb/>
              venience to terminate the Ray of Sight with a
                <lb/>
              Line in thoſe Places which lie higher than the
                <lb/>
              reſt; whence letting fall a Perpendicular, we
                <lb/>
              may find the right Direction and Production of
                <lb/>
              our Lines. </s>
              <s>Having marked out the Lines
                <lb/>
              and Angles of our Trenches, we ought to
                <lb/>
              have, if poſſible, as ſharp and clear a Sight as
                <lb/>
              a certain
                <emph type="italics"/>
              Spaniard
                <emph.end type="italics"/>
              in our Days was fabulouſly
                <lb/>
              ſaid to have, who they tell us, could ſee the
                <lb/>
              loweſt Veins of Water that run under Ground,
                <lb/>
              as plainly as if they were above Ground. </s>
              <s>So
                <lb/>
              the many Things happen under the Surface of
                <lb/>
              Earth, which we know nothing of, as makes it
                <lb/>
              unſafe to truſt the Weight and Expence of a
                <lb/>
              Building to it. </s>
              <s>And, certainly, as in all the
                <lb/>
              reſt of the Structure, ſo eſpecially in the Foun­
                <lb/>
              dations, we ought to neglect no Precaution
                <lb/>
              which it becomes an accurate and diligent
                <lb/>
              Architect to take; for an Error in any other
                <lb/>
              Part does leſs Miſchief, and is more eaſily re­
                <lb/>
              medied, or better borne, than in the Founda­
                <lb/>
              tion; in which, a Miſtake is inexcuſable. </s>
              <s>But
                <lb/>
              the Ancicnts uſed to ſay, dig on, and good
                <lb/>
              Fortune attend you, till you find a ſolid Bot­
                <lb/>
              tom; for the Earth has ſeveral Strata, and
                <lb/>
              thoſe of different Natures; ſome ſandy, others
                <lb/>
              gravelly, ſome ſtony, and the like; under
                <lb/>
              which, at certain Depths, is a hard, firm
                <lb/>
              Bank, fit to ſupport the heavieſt Structure.
                <lb/>
              </s>
              <s>This alſo is various, and hardly like any thing of
                <lb/>
              its own kind in any Particular; in ſome Places
                <lb/>
              it is exceſſively hard, and ſcarce penetrable with
                <lb/>
              Iron; in others, fatter and ſofter; in ſome
                <lb/>
              Places blacker, in others whiter; which laſt
                <lb/>
              is reckoned the weakeſt of all; in ſome Places
                <lb/>
              chalky, in others, ſtony; in others, a Kind
                <lb/>
              of Potters Clay mixed with Gravel; of all
                <lb/>
              which, no other certain Judgment can be
                <lb/>
              made, but that the beſt is reckoned to be that
                <lb/>
              which is hardeſt to the Pick-axe, and which
                <lb/>
              when wetted does not diſſolve. </s>
              <s>And for this
                <lb/>
              Reaſon, none is thought firmer and ſtronger,
                <lb/>
              or more durable, than that which ſerves as a
                <lb/>
              Bottom to any Springs of Water in the Bowels
                <lb/>
              of the Earth. </s>
              <s>But it is my Opinion, that the
                <lb/>
              beſt Way is to take Counſel with diſereet and
                <lb/>
              experienced Men of the Country, and with
                <lb/>
              the neighbouring Architects; who, both from
                <lb/>
              the Example of old Structures, and from their
                <lb/>
              daily Practice in actual Building, muſt be the
                <lb/>
              beſt Judges of the Nature of the Soil, and
                <lb/>
              what Weight it is able to bear. </s>
              <s>There are
                <lb/>
              alſo Methods of proving the Firmneſs of the
                <lb/>
              Soil. </s>
              <s>If you roll any great Weight along the
                <lb/>
              Ground, or let it fall down from any Heighth,
                <lb/>
              and it does not make the Earth ſhake, nor
                <lb/>
              ſtir the Water ſet there on Purpoſe in a Baſon;
                <lb/>
              you may ſafely promiſe yourſelf a good, ſound
                <lb/>
              Foundation in that Place. </s>
              <s>But in ſome Coun­
                <lb/>
              tries there is no ſolid Bottom to be found any
                <lb/>
              where; as near the
                <emph type="italics"/>
              Adriatic,
                <emph.end type="italics"/>
              and about
                <emph type="italics"/>
              Ve­
                <lb/>
              nice,
                <emph.end type="italics"/>
              where, generally, there is nothing to be
                <lb/>
              met with but a looſe, ſoft Mud.</s>
            </p>
            <p type="margin">
              <s>
                <margin.target id="marg4"/>
              * Plate 4.
                <lb/>
                <emph type="italics"/>
              (facing
                <lb/>
              page 44)
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="head">
              <s>CHAP. III.</s>
            </p>
            <p type="main">
              <s>
                <emph type="italics"/>
              That the Nature of Places is various, and therefore we ought not to truſt any
                <lb/>
              Place too haſtily, till we have firſt dug Wells, or Reſervoirs; but that in
                <lb/>
              marſhy Places, we muſt make our Foundation with Piles burnt at the Ends,
                <lb/>
              and driven in with their Heads downward with light Beetles, and many
                <lb/>
              repeated Blows, till they are driven quite into the Head.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="main">
              <s>You muſt therefore uſe different Me­
                <lb/>
              thods for your Foundations, according
                <lb/>
              to the Diverſity of Places, whereof ſome are
                <lb/>
              lofty, ſome low, others between both, as the
                <lb/>
              Sides of Hills: Some again are parcht and
                <lb/>
              dry, as generally the Summits and Ridges of </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>