Sun. Feb 5th, 2023
This plaque honoring Robert Recorde is in the Tenby Museum in Wales.
Enlarge / This plaque honoring Robert Recorde is in the Tenby Museum in Wales.

Robert Recorde was one of those people who was so extraordinarily ahead of his time that he seemed destined to a tragic end. In the 16th century he made advances in economics, medicine, theology and poetry. But its greatest contribution is taught to every elementary school child, and it arguably laid the foundations of modern computer science. He invented the equal sign.

From urine to popular science

Recorde was born in 1510 in Tenby, Wales. At the age of 14 he entered Oxford University. At the age of 21 he taught mathematics there, although a scholarship was not his first career goal. In the following years he also earned a degree in medicine and wrote the beautifully titled monograph Physick’s urinaldescribing what a doctor could learn from a patient’s urine.

Or medicine turned out to be less fascinating than Recorde expected, or less lucrative. Over the next decade he moved from medicine to finance, overseeing mints in Bristol, London and Dublin. However, the life of the writer clearly appealed to him. He produced a large and varied body of work: theological treatises defending Protestantism, poems and, above all, textbooks.

Not only did Recorde explain astronomy, geometry and arithmetic in successive textbooks, but he also explained them in English. Earlier works on mathematics were written in Latin, meaning that the only people who could read them had already received extensive training. Recorde wrote in English for the British layman. He came up with his most famous invention for these busy pupils. His latest book, Witte’s Whetstonepublished in 1557, gave the world the equal sign.


Perhaps a man trained to study urine and control currency has a pragmatic mind. Recorde found it irritating to have to say over and over that one side of an equation was equal to the other. He wrote, with obvious exasperation and erratic spelling: “And to avoid the tedious repetition of these words, I shall, as I often do, place a few parallels.” Instead of using an expression to convey meaning, he would convey the same meaning with a symbol. What symbol is more suitable than a few lines of equal length? Nothing, Recorde explained, “no 2 thyngs, can be more equal.”

Recorde’s symbol initially failed to catch on. The language of Latin was still prevalent in the 16th century. Latin had a word for the concept, “aequalis,” and if more brevity was needed, people could shorten it to “ae” or “oe.” But contributing to the popularity of the equals sign was Recorde’s introduction, for English speakers, of the German symbols “+” and “-“. Combined with these signs, people could quickly express a mathematical equation in symbols with a minimum of wasted ink. Instead of writing, “A factore added to a quantity of three-eyes is equal to a dysfyrynic factore of why a quantity of four is taken away,” a mathematician could write, “x + 3 = y – 4”.

On the surface, this makes Robert Recorde an excellent trivia game subject, but not much more. John V. Tucker, professor of computer science at Swansea University and an avid researcher of computability theory, argues that Recorde is much more important than its reputation suggests. In Robert Recorde: The Life and Times of a Tudor MathematicianTucker describes how Recorde’s work laid the groundwork for computer science, at least among English-speaking people:

Computing is largely about collecting, creating and processing data. It is universal and ubiquitous because it is intimate with the work of the world… To understand the history of computers, we can follow the data, which leads us to practical mathematics and to writers such as Recorde.

Tucker believes that Recorde introduced Britain to the concepts of quantification and data in a way that was unfamiliar and world-changing. His instruction on how to apply mathematics to fields such as commerce, surveying, navigation, and astronomy imposed a new mindset on people who previously would have spoken of quantity in vague terms such as “a fair amount and a reasonable distance.” Recorde helped introduce precision, exact quantification and accurate comparison into everyday life.

Mathematics for everyone

It is clear that Recorde also ushered in a new way of talking about numbers. By choosing from Latin and German texts, he introduced English speakers to words such as ‘linear’, ‘naming’, ‘binomial’ and ‘equation’. He introduced mathematical meanings for words like “square,” “composite,” “rational,” and “irrational.” Robert Recorde taught people to speak a mathematician, or more importantly, a computer language.

His most famous invention is still part of this computer language. The equals sign was first used as part of a computer programming language in FORTRAN I, in 1957. The sign, and its variations such as == or ===, are still used by people who, like Robert Recorde, would prefer giving “avoid the tedious repetition of these words, equals.” Today, computer programmers are reaping the benefits of Recorde’s work by inventing an accurate, quantifiable, and efficient symbolic language to describe the world.

Unfortunately, Recorde was not hailed as a hero of rationality and mathematics education in his lifetime. Brilliant as he was, he forgot one of the basic rules of his time: the aristocracy always wins. Recorde was relieved of his duties at the Dublin Mint by the Earl of Pembroke. Whether this was due to a setback in some of the silver mines Recorde was forced to develop or because he was a Protestant when the devoutly Catholic Queen Mary came to the throne is up for debate.

Recorde chose to dispute it with the Earl and filed a felony charge against him. The Earl responded by filing a libel lawsuit. The count has won. In 1557, a needy Recorde was thrown into debtors’ prison, where he died a year later at the age of 48.

By akfire1

Leave a Reply

Your email address will not be published.