_Kossir_, which is 136 leagues, the
sea is thickly beset with shoals and shelves or reefs, composed of
_coral stone_, which grows like clustered trees spreading its branches
on all sides as is done by real _coral_, to which this stone bears so
strong resemblance that it deceives many who are not very skilful
respecting the growth and nature of coral.

This _coral stone_ is of two sorts, one of which is a very pure white,
and the other very _red_. In some places this _coral stone_ is covered
by great quantities of green ouze or sleech, and in other places it is
free from this growth. In some places this ouze or sleech is very bright
green, and in others of an orange-tawny colour. From _Swakem_ upwards,
the water of this sea is so exceedingly clear, that in many places the
bottom may be distinctly seen at the depth of 20 fathoms. Hence,
where-ever these shoals and shelves are, the water over them is of three
several colours, according to the colour of these rocks or shelves, red,
green, or white, proceeding from the colour of the ground below, as I
have many times experienced. Thus when the ground of the shoals is sand,
the sea over it appears _white_; where the coral-stone is covered with
_green_ ouze or sleech, the water above is greener even than the weeds;
but where the shoals are of _red_ coral, or coral-stone covered by _red_
weeds, all the sea over them appears very _red_. And, as this _red_
colour comprehends larger spaces of the sea than either the _green_ or
the _white_, because the stone of the shoals is mostly of _red coral_, I
am convinced that on this account it has got the name of the _Red Sea_,
and not the green sea or the white sea, though these latter colours are
likewise to be seen in perfection.

The means I used for ascertaining this secret of nature were these. I
oftentimes fastened my bark upon shoals where the sea appeared red, and
commanded divers to bring me up stones from the bottom. Mostly it was so
shallow over these shoals, that the bark touched; and in other places
the mariners could wade for half a league with the water only breast
high. On these occasions most of the stones brought up were of red
coral, and others were covered by orange-tawny weeds. Whether the sea
appeared _green_, I found the stones at the bottom were white coral
covered with green weeds; and where the sea was white I found a very
white sand. I have conversed often with the Moorish pilots, and with
persons curious in a