# Baker, Thomas

, an eminent mathematician in the
seventeenth century, the son of James Baker of Ikon in
Somersetshire, steward to the family of the Strangways of
Dorsetshire, was born at Ikon about the year 1625, and
entered in Magdalen-hall, Oxon, in the beginning of the
year 1640. In April 1645, he was elected scholar of Wadham college and did some little servicb to king Charles I.
within the garrison of Oxford. He was admitted bachelor
of arts, April 10, 1647, but left the university without completing that degree by determination. Afterwards he became vicar of Bishop’s-Nymmet in Devonshire, where he
lived many years in studious retirement, applying chiefly
to the study of the mathematics, in which he made very
great progress. But in his obscure neighbourhood, he was
neither known, nor sufficiently valued for his skill in that
useful branch of knowledge, till he published his famous
book. A little before his death, the members of the royal
society sent him some mathematical queries to which he
returned so satisfactory an answer, that they gave him a
medal with an inscription full of honour and respect. He
died at Bishop’s-Nymmet aforementioned, on the 5th of
June 1690, and was buried in his own church. His book
was entitled “The Geometrical Key, or the Gate of Equations unlocked, or a new Discovery of the construction of
all Equations, howsoever affected, not exceeding the fourth
degree, viz. of Linears, Quadratics, Cubics, Biquadratics,
and the rinding of all their roots, as well false as true, without the use of Mesolahe, Trisection of Angles, without
| Reduction, Depression, or any other previous Preparations
of Equations, by a Circle, and any (and that one only)
Farabole, &c.” London, 1684, 4to, in Latin and English.
In the Philosophical Transactions, it is observed, that the
author, in order to free us of the trouble of preparing the
equation by taking away the second term, shews us how to
construct all affected equations, not exceeding the fourth
power, by the intersection of a circle and parabola, without omission or change of any terms. And a circle and a
parabola being the most simple, it follows, that the way
which our author has chosen is the best. In the book (to render it intelligible even to those who have read no conies), the author shews, how a parabola arises from the
section of a cone, then bow to describe it in piano, and
from that construction demonstrates, that the squares of
the ordinates are one to another, as the correspondent
sagitta or intercepted diameters then he shews, that if a
line be inscribed in a parabola perpendicular to any diameter, a rectangle made of the segments of the inscript,
will be equal to a rectangle rr.ade of the intercepted diameter and parameter of the axis. From this last propriety
our author deduces the universality of his central rule for
the solution of ai! 2 biquadratic and cubic equations, however
affected or varied in terms or signs. After the synthesis
the author shews the analysis or method, by which he found
this rule which, in the opinion of Dr. R. Plot (who was then secretary to the royal society) is so good, that nothing can be expected more easy, simple, or universal. ^{1}

^{1}Bio. Brit.-—Ath. Ox, vol. II.