John Wallis

“John Davys, John Wallis, An Essay on the Art of Decyphering: In which is inserted a discourse of Dr. Wallis. Now first publish'd from his original manuscript in the publick library at Oxford (1737)”

“Henry Briggs, John Wallis, Edmond Halley, Abraham Sharp, Mathematical Tables Contrived after a most Comprehensive Method (1717)”

“Jakob Bernoulli, John Wallis, The Doctrine of Permutations and Combinations (1795)”

“"Dr. Wallis's Account of some Passages of his own Life" (1696) as contained in part XII of Peter Langtoft's Chronicle (1725)”

“Wallis used Arithmetic of infinities to produce genuine understanding rather than brutal persuasion.”

“Based on a pattern he observed in the characters of the first few {{w|figurate number}}s, Wallis conceived a procedure for generating further characters. ...Wallis explained how to use figurate numbers to measure areas and volumes and, eventually, to square the circle. ...[H]e demphasized traditional forms of mathematical demonstration ...taking ...analysis as a way of finding. He believed he could promote mathematics more by exposing his own investigations than through sterile demonstrations.”

“[I]n On conic sections, Wallis... claimed that algebra would enable an 'absolute contemplation' of the conic sections by directly expressing... 'primary and essential affections' from which secondary affections could be 'deduced by calculation'. ...Both the use of symbols to express essences and their manipulation to obtain easy results characterized Wallis...”

“Newton opposed entangled and tedious algebraic calculations to simple, elegant geometric constructions; Wallis opposed difficult, embrangled geometric diagrams to simplified, rationally lettered diagrams and the symbolic expressions they enabled.”

“By regularizing... symbols Wallis circumvented the typical role of diagrams in geometric argument. ...Wallis’s new lettering strategy meant that the reader would not have to constantly look back at the diagram to understand the argument... the reader might recognize from the letters which parts of the cone were signified.”

“Wallis saw Greek diagrams as intricate and confused. His own... clearly displayed the conic sections and the key lines characterizing... their ‘essential affections’... More importantly, he used the same diagram as often as possible and, when not... changed the diagram only minimally. ...[He] claim[ed]... his 1685 Treatise on algebra... considered the sections 'abstractly as Figures in plano, without the embranglings of the Cone'.”

“Seventeenth-century proponents of symbols frequently advanced the fecundity of their approach as evidence for its superiority over classical mathematics: Wallis’s Arithmetic of infinities displayed results 'neither discovered by nor known to others', and René Descartes’s 1637 Geometry announced its general solution to a family of problems that the Greeks had left mostly unsolved. ...Newton, inspired ...by these ...texts ...used symbols to invent an algorithmic version of the calculus.”

“The association between geometric synthesis and 'common' understanding was not Newton’s innovation: many of Newton’s predecessors, including Wallis, endorsed it.”

“Wallis... denigrat[ed] synthetic demonstration for its failure to bring clarity to mathematical investigation.”

“Wallis’s 1656 Arithmetic of infinities was a crucial text for Newton’s development of calculus, a fact that Newton... related to Gottfried Leibniz in a... letter.”

“In his 1657 Mathesis universalis... Wallis printed geometric representations of the first 10 propositions of book II of the Elements alongside symbolic 'arithmetical' demonstrations and worked examples in numbers; he believed that the symbolic treatment was more general.”

“Among his interesting discoveries was the relation    \frac{4}{\pi} = \frac32\cdot\frac34\cdot\frac54\cdot\frac56\cdot\frac76\cdot\frac78\cdotsone of the early values of π involving infinite products.”

“His writings include works on mechanics, sound, astronomy, the tides, the laws of motion, the Torricellian tube, botany, physiology, music, the calendar (in opposition to the Gregorian reform), geology, and the compass,—a range too wide to allow of the greatest success in any of the lines of his activity. He was also an ingenious cryptologist and assisted the government in deciphering diplomatic messages.”

“Wallis was in sympathy with Greek mathematics and astronomy, editing parts of the works of Archimedes, Eutocius, Ptolemy, and Aristarchus; but at the same time he recognized the fact that the analytic method was to replace the synthetic, as when he defined a conic as a curve of the second degree instead of as a section of a cone, and treated it by the aid of coordinates.”

“In 1673 he wrote his great work De Algebra Tractatus; Historicus & Practicus, of which an English edition appeared in 1685. In this there is seen the first serious attempt in England to write on the history of mathematics, and the result shows a wide range of reading of classical literature of the science. This work is also noteworthy because it contains the first of an effort to represent the imaginary number graphically by the method now used. The effort stopped short of success but was an ingenious beginning.”

“Lord Brounckner... communicated without proof to Wallis the [{{w|continued fraction}}] expression{{center/s}}\frac{4}{\pi} = 1 + \frac {1}{2 +} \frac {9}{2 +} \frac {25}{2 +} \frac {49}{2 +}\cdots,{{center/e}}a proof of which was given by Wallis in his Arithmetica Infinitorum. It was afterwards shewn by Euler that Wallis' formula could be obtained from the development of the sine and cosine in infinite products, and that Brounckner's expression is a particular case of much more general theorems.”