, **an** Arabian author, who is supposed to have lived about the fourth

**an**, **an** **Arabian** **author**, who is supposed to have
lived about the fourth century, and is styled the son of
Seirim, wrote a book “On the interpretation of Dreams,
according to the doctrine of the Indians, the Persians, and
the Egyptians,

” which, with all its absurdities, has been
translated into Greek and Latin, and published, together
with “Artemidorus on Dreams and Chiromancy,

” by M.
Rigault in Paris,

e on the twilight, which he dedicated to John III. king of Portugal; to which he added what Alhazen, **an** Arabian author, has composed on the same subject. In this work

**an**In 1542 he published a treatise on the twilight, which
he dedicated to John III. king of Portugal; to which he
added what Alhazen, **an** **Arabian** **author**, has composed on
the same subject. In this work he describes the method
or instrument erroneously called, from him, a Nonius.
He corrected several mathematical mistakes of Orontius
Finasus. But the most celebrated of all his works, or that
at least he appeared most to value, was his “Treatise of
Algebra,

” which he had composed in Portuguese, but
translated it into the Castilian tongue when he resolved
upon making it public, which he thought would render
his book more useful, as this language was more
generally known than the Portuguese. The dedication to
his former pupil, prince Henry, was dated from Lisbon,
Dec. 1, 1564. This work contains 341 pages in the Antwerp edition of 1567, in 8vo. The catalogue of his works,
chiefly in Latin, is as follows: 1. “De Arte Navigandi,
libri duo,

” De Crepusculis,

” Annotationes in Aristotelem.

” 4. “Problema Mechanicum
de Motu Navigii ex Remis.

” 5. “Annotationes in Planetarum Theorias Georgii Purbachii,

” &c. 6. “Libro
de Algebra en Arithmetica y Geometra,

” De Crepusculis,

” consists in describing within the same
quadrant, 45 concentric circles, dividing the outermost
into 90 equal parts, the next within into 89, the next into
88, and so on, till the innermost was divided into 46 only.
By this means, in most observations, the plumb-line or index must cross one or other of those circles in or very near
a point of division: whence by calculation the degrees and
minutes of the arch might easily be obtained. This method is also described by him in his treatise “De Arte
Navigandi,

” where he imagines it was not unknown to
Ptolomy. But as the degrees are thus divided unequally,
and it is very difficult to attain exactness in the division,
especially when the numbers, into which the arches are
to be divided, are incomposite, of which there are no less
than uine, the method of diagonals, first published by
Thomas Digges, esq. in his treatise “Alae seu Scaloe Mathematicae,

” printed at Lond. in