SUPPOSED PIKATICAL VESSEL. 
On tlie morning of the 1st of December, the sea slowly 
calmed, and the breeze became steady from N.E. On the 
we descried Cape Beata, in a spot wliere 
we had long observed the clouds gathered togetlier. Accord- 
mg to the observations of Aclieruer, which I obtained 
m the nigiit, wc W’ere sixty-four miles distant. Durino- the 
night tliere was a very curious optical phenomenon, which 
1 shall not undertake to account for. At half-iiast midiii'dit 
the east ; the thormometer rose 
to _ tile whalebono hygrometer was at 57°. I liad 
remained upon llie deck to observe the culmination of some- 
stars. 1 he iiill-moon was high in the heavens. Suddenly, 
in the direction ot the moon, 45'^ before its passan-e o\-er 
the meridian, a great arch was formed tinged with the pris- 
matic colours, though not of a bright ' hue. The arch 
appeared higher than the moon; this iris-band was near 
2 broad, and its summit seemed to rise nearly from S0“ 
to So“ above the horizon of the sea. The sky was siiio-iilarly 
pure ; there w.as no appearance of rain ; and what'striick 
me most was, that this plieiiomenoii, which perfectly resem- 
bled a lunar rainbow, was not in the direction opposite to 
the moon. the arch remained stationary, or at least 
appeared to do so, during eight or ten miiuites ; and at 
the moiiicnt when I tried if it wore possible to seo it by 
reilec.tioii in the mirror of the sextant, it began to move 
and descend, crossing successively the IVloon and Jupiter. 
It ^\us 12 5-1'*^ (moan time) when the smniuifc of the 
arch sank below tlie horizon. This movement of an arch, 
coloured like the rainbow, filled with astonishment the 
sailors who were on watch on the deck. They alleged, 
as they do on the appearance of every extraordinary me- 
teor, that it denoted wind. M. Arago examined the sketch 
ol this arch in my journal; and he is of opinion that the 
image of the moon reflected in the waters could not have 
given a halo of such great dimensions. The rapidity of (he 
movement is no small obstacle in the way of exiiianatioii 
of a plicnomenon well worthy of attention. 
On the 3rd of December we felt some uneasiness on aceouiit 
of the jiroximity of a small vessel supposed to be a pirate, 
but -vvyich, as it drew near, we recognized to be the Balan- 
dra del Brayle, (the sloop of the Monk). I was at a loss to 
