
to Newton. In fact, Newton did not discover Taylor
series until 1691 and that discovery, hidden in his pri-
vate papers, did not come to light until 1976!
Brook Taylor (16851731)
Brook Taylor was born into a well-to-do family with
connections to the nobility. Although he studied law at
Cambridge, his scientific career was already under way
by the time he graduated. Encouraged by contacts at
the Royal Society to develop and communicate his
discoveries, Tay lor privately disclosed the series that
now bears his name in a letter of 1712. He first publicly
communicated his work on series in his book, The
Method of Increments, which appeared in 1715. At the
time, the unpublished work of Gregory and Newton
remained unknown. Johann Bernoulli and Abraham
De Moivre had published anticipations of Taylor series
in 1694 and 1708, but they did not deny Tay lor’s claim
to priority. Moreover, Taylor’s immediate successors,
including Maclaurin and Euler, credited him not only
for introducing Taylor series, but also for demonstrat-
ing the uses to which they can be put. The term Taylor
series has been traced to 1786, after which it quickly
became established. By the mid-1800s, one writer
commented, “A single analytical formula in the
Method of Increments has conferred a celebrity on its
author, which the most voluminous works have not
often been able to bestow.” It is ironic, then, that
Taylor series were known to Gregory fourteen years
before Taylor was born and the error term, which is a
crucial compo nent of Taylor’s Theorem in practice, was
introduced by Lagrange several years after Taylor’s
death.
Colin Maclaurin (16981746)
Colin Maclaurin was born a minister’s son. Orphaned
at the age of nine, he became the ward of an uncle, who
was also a minister. The precocious boy entered the
University of Glasgow just two years later. The plan
was that he too would become a minister. At the age of
twelve, however, Maclaurin discovered the Elements of
Euclid and was led astray. Within a few days he mas-
tered the first six books of Euclid. His interest in
mathematics did not wane thereafter. Three years later,
at the age of fifteen, he defended his thesis on Gravity
and graduated from university.
The young Maclaurin had to bide his time for a few
years, but he was still only nineteen when, in 1717, he
was appointed Professor of Mathematics at the Uni-
versity of Aberdeen. In the next two years, he forged a
warm friendship with Sir Isaac Newton, a bond that
Maclaurin described as his “greatest honour and hap-
piness.” On Newton’s recommendation, the University
of Edinburgh offered Maclaurin a professorship in
1725. It came in the nick of time—Aberdeen was about
to dismiss Maclaurin for being absent without leave for
nearly three years. His teaching at Edinburgh had
happier results. One student wrote that “He made
mathematics a fashionable study.”
Maclaurin’s research also received the highest
praise. Lagrange described Maclaurin’s study of tides
as “a masterpiece of geometry, comparable to the most
beautiful and ingenious results that Archimedes left to
us.” Maclaurin’s Treatise of Fluxions, which appeared
in 1742, is considered his major work. He conceived it
as an answer to the criticisms of Bishop Berkeley that
have been discussed in Genesis and Development 2 and
3. Although Maclaurin series are to be found in the
Treatise of Fluxions, Maclaurin himself attributed them
to Taylor. Thus the terminology Maclaurin series is not
historically justified. Nonetheless, it is convenient—it
saves us from having to say “Taylor series expanded
about 0.” Furthermore, it is appropriate to remember
this great mathematician in some way. Ideas such as the
Integral Test that Maclaurin did introduce in his
Treatise do not be ar his name.
720 Chapter 8 Infinite Series