tise on the calculus of finite differences. It
contained the well-known theorem that bears his name.

[529] Pierre Louis Moreau de Maupertuis (1698-1759) was sent with Clairaut
(1735) to measure an arc of a meridian in Lapland. He was head of the
physics department in the Berlin Academy from 1745 until 1753. He wrote
_Sur la figure de la terre_ (1738) and on geography and astronomy.

[530] Pierre Bouguer (1698-1758) was professor of hydrography at Paris, and
was one of those sent by the Academy of Sciences to measure an arc of a
meridian in Peru (1735). The object of this and the work of Maupertuis was
to determine the shape of the earth and see if Newton's theory was
supported.

[531] Charles Marie de la Condamine (1701-1774) was a member of the Paris
Academy of Sciences and was sent with Bouguer to Peru, for the purpose
mentioned in the preceding note. He wrote on the figure of the earth, but
was not a scientist of high rank.

[532] See Vol. I, page 136, note 5 {283}.

[533] See Vol. II, page 296, note 483.

[534] Thomas Baker (c. 1625-1689) gave a geometric solution of the
biquadratic in his _Geometrical Key, or Gate of Equations unlocked_ (1684).

[535] See Vol. I, page 160, note 5 {350}.

[536] See Vol. I, page 87, note 4 {133}.

[537] See Vol. I, page 132, note 2 {272}.

[538] See Vol. I, page 118, second note 1 {231}.

[539] The name of Newton is so well known that no note seems necessary. He
was born at Woolsthorpe, Lincolnshire, in 1642, and died at Kensington in
1727.

[540] John Keill (1671-1721), professor of astronomy at Oxford from 1710,
is said to have been the first to teach the Newtonian physics by direct
experiment, the apparatus being invented by him for the purpose. He wrote
on astronomy and physics. His _Epistola de legibus virium centripetarum_,
in the Philosophical Transactions for 1708, accused Leibnitz of having
obtained his ideas of the calculus from Newton, thus starting the priority
controversy.

[541] Thomas Digges (d. in 1595) wrote _An Arithmeticall Militare Treatise,
named Stratioticos_ (1579), and completed _A geometrical practise, named
Pantometria_ (1571) that had been begun by his father, Leonard Digges.

[542] John Dee (1527-1608), the most famous astrologer of his day, and
something of a mathematician, wrote a preface to Billingsley's translation
of Euclid into English (1570).

[543] See Vol. I, page 76, note 3 {112}.

[544] Thomas Harriot (1560-1621) was tutor in