"... and then we saw a Corpus Sant at our Main-top-mast Head, on the very Top of the Truck of the Spindle.
This sight rejoiced our Men exceedingly, for the height of the Storm is commonly over when the Corpus Sant is seen aloft.
But when they are seen lying on the Deck, it is generally accounted a bad Sign.
"A Corpus Sant is a certain small glittering Light.
When it appears, as this did, on the very Top of the Main-mast or at a Yard-arm, it is like a Star.
But when it appears on the Deck, it resembles a great Glow-worm..."