of his father, privately printed at Oxford in
1883.

[498] See Vol. I, page 69, note 3 {96}.

[499] See Vol. I, page 106, note 4 {188}.

[500] William Gascoigne was born at Middleton before 1612 and was killed in
the battle of Marston Moor in 1644. He was an astronomer and invented the
micrometer with movable threads (before 1639).

[501] Seth Ward (1617-1689) was deprived of his fellowship at Cambridge for
refusing to sign the covenant. He became professor of astronomy at Oxford
(1649), Bishop of Exeter (1662), Bishop of Salisbury (1667), and Chancellor
of the Garter (1671). He is best known for his solution of Kepler's problem
to approximate a planet's orbit, which appeared in his _Astronomia
geometrica_ in 1656.

[502] See Vol. I, page 110, note 2 {198}.

[503] See Vol. I, page 100, note 2 {172}.

[504] See Vol. I, page 107, note 1 {190}.

[505] See Vol. I page 114, note 6 {220}.

[506] See Vol. I, page 77, note 4 {118}.

[507] See Vol. I, page 125, note 3 {253}.

[508] See Vol. I, page 105, note 2 {186}.

[509] Heinrich Oldenburgh (1626-1678) was consul in England for the City
of Bremen, his birthplace, and afterwards became a private teacher in
London. He became secretary of the Royal Society and contributed on
physics and astronomy to the _Philosophical Transactions_.

[510] Thomas Brancker, or Branker (1636-1676) wrote the _Doctrinae
sphaericae adumbratio et usus globorum artificialium_ (1662) and
translated the algebra of Rhonius with the help of Pell. The latter work
appeared under the title of _An Introduction to Algebra_ (1668), and
is noteworthy as having brought before English mathematicians the
symbol / for division. The symbol never had any standing on the
Continent for this purpose, but thereafter became so popular in England
that it is still used in all the English-speaking world.

[511] See Vol. I, page 118, note 1 {230}.

[512] Pierre Bertius (1565-1629) was a native of Flanders and was educated
at London and Leyden. He became a professor at Leyden, and later held the
chair of mathematics at the College de France. He wrote chiefly on
geography.

[513] See Vol. II, page 297, note 487.

[514] Giovanni Alphonso Borelli (1608-1679) was professor of mathematics at
Messina (1646-1656) and at Pisa (1656-1657), after which he taught in Rome
at the Convent of St. Panteleon. He wrote several works on geometry,
astronomy, and physics.

[515] See Vol. I, page 172, note 2 {381}.

[516] Ign