Edges and corners of a square sail are shown on the uppermost sail:
<ul><li>The sail is attached to a <i>spar</i> (or <i>yard</i>) at its <i>head</i> and tensioned outwards at the <i>head cringles</i>.</li>
<li>The side edges are the <i>leeches</i>.</li>
<li>The bottom edge is the <i>foot</i> and is attached to the yard below by sheets (not labelled) at the <i>clews</i> which are the corners.</li></ul><p>Running rigging is shown on the lower sail:
</p>
<ul><li>The <i>lifts</i> are shown slack, because the spar (or yard) is raised, but would support the lowered spar, as shown on the topmost spar.</li>
<li>The <i>sheets</i> pull the clews down to the yard below when setting sail.</li>
<li>The <i>clewlines</i> raise the clews to the yard above when dousing (striking or furling) sail.</li>
<li>The <i>halyard</i> raises a yard into place, seen as two line converging on a block, which is attached to a line that goes up to the crosstrees and through a sheave to raise the yard.</li>
<li>The <i>braces</i> adjust the sail side-to-side by tension applied from below to a block on the spar, countered by tension at the other end on a mast behind the spar, pulling one end aft and allowing the other end to rotate forward.</li></ul>
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