d other places. He wrote several
works on astronomy.

[184] "And I, if I be lifted up from the earth, will draw all men unto me."
John xii. 32.

[185] Andrea Argoli (1568-1657) wrote a number of works on astronomy, and
computed ephemerides from 1621 to 1700.

[186] So in the original edition of the _Budget_. It is Johannem Pellum in
the original title. John Pell (1610 or 1611-1685) studied at Cambridge and
Oxford, and was professor of mathematics at Amsterdam (1643-46) and Breda
(1646-52). He left many manuscripts but published little. His name attaches
by accident to an interesting equation recently studied with care by Dr.
E. E. Whitford (New York, 1912).

[187] Christianus Longomontanus (Christen Longberg or Lumborg) was born in
1569 at Longberg, Jutland, and died in 1647 at Copenhagen. He was an
assistant of Tycho Brahe and accepted the diurnal while denying the orbital
motion of the earth. His _Cyclometria e lunulis reciproce demonstrata_
appeared in 1612 under the name of Christen Severin, the latter being his
family name. He wrote several other works on the quadrature problem, and
some treatises on astronomy.

[188] The names are really pretty well known. Giles Persone de Roberval was
born at Roberval near Beauvais in 1602, and died at Paris in 1675. He was
professor of philosophy at the College Gervais at Paris, and later at the
College Royal. He claimed to have discovered the theory of indivisibles
before Cavalieri, and his work is set forth in his _Traite des
indivisibles_ which appeared posthumously in 1693.

Hobbes (1588-1679), the political and social philosopher, lived a good part
of his time (1610-41) in France where he was tutor to several young
noblemen, including the Cavendishes. His _Leviathan_ (1651) is said to have
influenced Spinoza, Leibnitz, and Rousseau. His _Quadratura circuli,
cubatio sphaerae, duplicatio cubi ..._ (London, 1669), _Rosetum geometricum
..._ (London, 1671), and _Lux Mathematica, censura doctrinae Wallisianae
contra Rosetum Hobbesii_ (London, 1674) are entirely forgotten to-day. (See
a further note, _infra_.)

Pierre de Carcavi, a native of Lyons, died at Paris in 1684. He was a
member of parliament, royal librarian, and member of the Academie des
Sciences. His attempt to prove the impossibility of the quadrature appeared
in 1645. He was a frequent correspondent of Descartes.

Cavendish (1591-1654) was Sir (not Lord) Charles. He was, like De Morgan
himself, a bibliophile