kal. April, visa est in Sole qualis parva macula nigra, paulultrm superius
medio centro ejnsdem sideris, quce a nobis octo dies conspicata est ; sed
quando primurn intravit vel exivit, nubibus impedientibus, minime no
tare potuimus." " On the 15th of March, DCCCCVII., Mercury ap
peared to be a small black spot on the Sun, a little above his center,
and was visible to us in that position for eight days ; but, owing to the
obstruction offered by the clouds, we were not able to see either when
it reached or left that place." The so-called transit of Venus recorded
by the Arabian astronomers, is noticed by Simon Assemanus in the In-
troduction to the Globus Calestis Cvfico-Ardbicus Veliterni Musei Bor-
giani, 1790, p. xxxviii. : " Anno HegyrsB 225, regnante Almootasemo
Chalifa, visa est in Sole prope medium nigra quiedam macula, idque

feria tertia die decima nona mensis Regebi " This appearance

was believed to be the planet Venus, and the same black spot (macula
nigra) was supposed to have been seen for 91 days (probably with in-
termissions of twelve or thirteen days?). Soon after this, the reigning
Calif Motassem died. I have selected the following seventeen exam
pies from a large number of facts collected from the historical records
derived from popular tradition, as to the occurrence of a sudden de
crease in the light of the Sun :

45 B.C. At the death of Juhus Caesar: after which event the Sun re-
mained pale for a whole year, and gave less than its usual warmth ;
on which account the air was thick, cold, and hazy, and fruit did not
ripen. — Plutarch in J«Z. Cws., cap. 87; Dio Coss., xliv.; Virg., Georg-.,
i., 466.
