SPHERICAL TRIANGLE. That contained under three arcs of great circles of a sphere.
SPHEROID. The figure formed by the rotation of an ellipse, differing little from a circle.
SPICA, OR α Virginis. The lucida of Virgo, a standard nautical star.
SPIDER. An iron out-rigger to keep a block clear of the ship's side.
SPIDER-HOOP. The hoop round a mast to secure the shackles to which the futtock-shrouds are attached. Also, an iron encircling hoop, fitted with belaying pins round the mast.
SPIDER-LINES. A most ingenious substitution of a spider's long threads for wires in micrometer scales, intended for delicate astronomical observations.
SPIKE-NAILS. See [Deck-nails].
SPIKE-PLANK. (Speak-plank?) In Polar voyages, a platform projecting across the vessel before the mizen-mast, to enable the ice-master to cross over, and see ahead, and so pilot her clear of the ice. It corresponds with the bridge in steamers.
SPIKE-TACKLE AND CANT-FALLS. The ropes and blocks used in whalers to sling their prey to the side of the ship.
SPIKE-TUB. A vessel in which the fat of bears, seals, and minor quarry is set aside till a "making off" gives an opportunity for adding it to the blubber in the hold.