eilfte Axiom der Elemente des Euclidis neu bewiesen_ in 1859.
He wrote other works on mathematics, but none of his contributions was of
any importance.

[517] Johann Karl Friedrich Hauff (1766-1846) was successively professor of
mathematics at Marburg, director of the polytechnic school at Augsburg,
professor at the Gymnasium at Cologne, and professor of mathematics and
physics at Ghent. The work to which Kircher refers is his memoirs on the
Euclidean _Theorie der Parallelen_ in Hindenburg's _Archiv_, vol. III
(1799), an article of no merit in the general theory.

[518] Wenceslaus Johann Gustav Karsten (1732-1787) was professor of logic
at Rostock (1758) and Butzow (1760), and later became professor of
mathematics and physics at Halle. His work on parallels is the _Versuch
einer voellig berichtigten Theorie der Parallellinien_ (1779). He also wrote
a work entitled _Anfangsgruende der mathematischen Wissenschaften_ (1780),
but neither of these works was more than mediocre.

[519] Johann Christoph Schwab (not Schwal) was born in 1743 and died in
1821. He was professor at the Karlsschule at Stuttgart. De Morgan's wish
was met, for the catalogues give "c. fig. 8," so that it evidently had
eight illustrations instead of eight volumes. He wrote several other works
on the principles of geometry, none of any importance.

[520] Gaetano Rossi of Catanzaro. This was the libretto writer (1772-1855),
and hence the imperfections of the work can better be condoned. De Morgan
should have given a little more of the title: _Solusione esatta e regolare
... del ... problema della quadratura del circolo_. There was a second
edition, London, 1805.

[521] This identifies Rossi, for Josephine Grassini (1773-1850) was a
well-known contralto, _prima donna_ at Napoleon's court opera.

[522] William Spence (1783-1860) was an entomologist and economist of some
standing, a fellow of the Royal Society, and one of the founders of the
Entomological Society of London. The work here mentioned was a popular one,
the first edition appearing in 1807, and four editions being justified in a
single year. He also wrote _Agriculture the Source of Britain's Wealth_
(1808) and _Objections against the Corn Bill refuted_ (1815), besides a
work in four volumes on entomology (1815-1826) in collaboration with
William Kirby.

[523] "That used to be so, but we have changed all that."

[524] "Meet the coming disease."

[525] George Douglas (or Douglass) was a Sco