d have occurred about October 1508, and the victory
of the Adda was on May 14, 1509. This fact fixes his birth in 1501, and
shows that his illness must have lasted six or seven months.

[17] _De Vita Propria_, ch. iv. p. ii.

[18] _Opera_, tom. i. p. 676.

[19] "Quod munus profitendi institutiones in urbe ipsa cum honorario
centum coronatorum, quo jam tot annis gaudebat, non in me (ut speraverat)
transiturum intelligebat."--_De Vita Propria_, ch. x. p. 35.

[20] "Pater jam ante concesserat ut Geometriae et Dialecticae operam darem,
in quo (quanquam praeter paucas admonitiones, librosque, ac licentiam,
nullum aliud auxilium praebuerit) eas tamen ego (succicivis temporibus
studens) interim feliciter sum assecutus."--_De Consolatione_, Opera, tom.
i. p. 619.

[21] "Facius Cardanus daemonem aetherium, ut ipse dicebat, diu familiarem
habuit; qui quamdiu conjuratione usus est, vera illi dabat responsa, cum
autem illam exussisset, veniebat quidem, sed responsa falsa dabat. Tenuit
igitur annis, ni fallor, vinginti octo cum conjuratione, solutum autem
circiter quinque."--_De Varietate_, p. 629.

In the _Dialogus Tetim_ (_Opera_, tom. i. p. 672), Cardan writes: "Pater
honeste obiit et ex senio, sed multo antea eum Genius ille reliquerat."

[22] There is a discrepancy between this date and the one given in _De
Vita Propria_, ch. iv. p. 11. "Anno exacto XIX contuli me in Ticinensem
Academiam."

[23] "Inde (desiderium augente absentia) mortuus est, saeviente peste, cum
primum me diligere coepisset."--_De Consolatione_, Opera, tom. i. p. 619.

[24] _De Utilitate_, p. 348.

[25] "Nimis satis fuit defuisse tot, memoriam, linguam Latinam per
adolescentiam."--_De Vita Propria_, ch. li. p. 218.

[26] John Peckham was a Franciscan friar, and was nominated to the see of
Canterbury by Nicholas III. in 1279. He had spent much time in the convent
of his Order at Oxford, and there is a legend connecting him with a
Johannes Juvenis or John of London, a youth who had attracted the
attention and benevolence of Roger Bacon. This Johannes became one of the
first mathematicians and opticians of the age, and was sent to Rome by
Bacon, who entrusted to him the works which he was sending to Pope Clement
IV. There is no reason for this view beyond the fact that both were called
John, and distinguished in the same branches of learning. The _Perspectiva
Communis_ was his principal work; it does not deal with perspective as now
understood, but w