Thomas Fowler – Complete Biography, History, and Inventions

A page in one of Thomas Fowler's published books.

Thomas Fowler – Complete Biography, History, and Inventions

Innovation and invention abounded throughout the 1800s. Countless men and women of all sorts of different backgrounds and disciplines were hard at work forming the ideas that would eventually become the inventions that would eventually become the computer technology we know and love today.

Thomas Fowler was one such person whose genius ideas in the 1800s helped establish the basis for the essential tech we still rely on to this day.

But who was this inventor, and what exactly did he invent? Let’s begin with who Thomas Fowler was.

Who Was Thomas Fowler?

Thomas Fowler was a man of many different disciplines. An Englishman with experience as a cooper, a fellmonger, self-taught mathematics, a printer and bookseller, and a treasurer, Fowler touched on many different aspects of daily life in Britain in the late 1700s and early 1800s — and conceived inventions to improve each one of these different aspects. As such, Fowler was ultimately an inventor above all else.

Early Life

Much of what is known about Thomas Fowler’s early life before becoming an inventor comes from a biography assembled by his son Hugh. Born in Great Torrington, Devon, England sometime in 1777, Thomas Fowler’s mother and father, Elizabeth and Hugh Fowler lived humble lives in their small market town. Hugh was a cooper — the maker of wooden barrels, tubs, casks, buckets, assembled from heated or steamed wooden staves — and trained Thomas in his craft from the young age of 13.

According to Thomas’s son Hugh, Fowler’s education lacked anything more than basic reading, writing, and arithmetic skills. What he lacked in formal schooling he more than made up for with his reading for leisure and his real-world experience as a fellmonger-in-training. As a matter of fact, these two factors are what eventually gave him the ideas for the inventions that would change his life and ensure his name would be etched into the history of the early calculator forever.

Fowler would teach himself far more than he ever learned in school by obsessively reading and rereading books such as John Ward’s Young Mathematician’s Guide and Nicholas Saunderson’s The Method of Fluxions. He then took what he learned in the pages of these books and applied them to his eventual creation of the early calculator.


Despite his minimal formal education, Thomas Fowler still managed to become a self-taught English inventor for the history books. From bookstores to bank vaults, from printing presses to patents, each new twist and turn in Fowler’s career path brought him closer to the invention of the calculating machine, an early calculator that came in handy during his career in banking and would have been just as useful during his years in publishing. Let’s take a closer look at his career as a whole.

Printer and Bookseller

After his short-lived apprenticeship as a cooper, Fowler focused his energy on becoming a printer and a bookseller. At this time in the late 1700s and early 1800s, this wasn’t as simple as sending some papers to your wireless printer or taking a book off the shelf at Barnes & Noble: printing and bookselling was a very meticulous and incredibly arduous process, one that required extreme attention to detail and the skill of a craftsman to be able to work the printer and assemble the exquisite, leather-bound editions he had for sale.

Banker and Treasurer

After his time as a printer and a bookseller, Fowler pivoted toward banking and acting as treasurer for a couple of different financial institutions in Great Torrington. Before long, he was a partner and manager of the bank Messrs Loveband & Co. as well as the acting treasurer of Torrington Poor Law Union. The amount of time Fowler spent calculating payments directly resulted in his invention of binary and ternary tables and, eventually, the calculating machine.


In the 15 years between 1828 and his death in 1843, Thomas Fowler invented three completely separate but equally important devices. Each invention came from the need he faced in his daily life as a banker and treasurer: the need to circumvent the long and arduous mathematical processes of banking. It seems safe to say his career as an inventor is the greatest of his great many numbers of different jobs.

A page in one of Thomas Fowler’s published books.

What Did Thomas Fowler Invent?

Unlike some other English inventors of the time, Thomas Fowler wasn’t just a one-hit-wonder: He was a man of many talents and many inventions. These included his binary and ternary tables, his calculating machine, and his thermosiphon.

Binary and Ternary Tables

During his time as treasurer, Fowler found himself having to do all sorts of complicated and time-consuming calculations. Using the knowledge gained from his math books, Fowler created a mathematical system that used lower bases to simplify his many complex calculations. In 1838, he published his first work — Tables for Facilitating Arithmetical Calculations.

This publication detailed his first invention: a table of binary numbers from 1 to 130,048, and a table of balanced ternary numbers from 1 to 3,985,807. His publication explained how these novel tables worked and how a person could simplify math with them.

Calculating Machine

As a natural extension of his binary and ternary tables, Fowler soon invented a proper calculating machine that served as an early calculator for the banker — almost like a better abacus. This machine brought Fowler’s tables to life, underlining his realization that all numbers could be produced by combining powers of 2 or 3.

It consisted of four separate parts:

The first, second and third displayed the quotient, divisor, and dividend or the multiplicand, multiplier, and product, depending on whether the problem was multiplication or division. The fourth part was a carrying apparatus, which was used to reduce the answer to its simplest form. It relied on a series of rods to enter numbers and display its answer, and Fowler built it all by hand using wood from his workshop.


Beyond all this math, Fowler also had an interest in creating a central convective heating system for homes and businesses in the 1800s — the first step toward the HVAC systems most modern homes come equipped with today. Fowler realized that it would be possible to force and circulate the warm air from heated water through a siphon and horizontal pipes, provided that the height of the siphon always be less than the pressure of the atmosphere so that balance could be maintained.

Sadly for Fowler and his future descendants, due to the incredibly flawed patent system of the 1800s, even the slightest change to an invention could render the former patent useless. As such, the thermosiphon was ripped off by countless other inventors and Fowler couldn’t do a thing about it — effectively robbing him of a great deal of notoriety and profits. 

Thomas Fowler: Marriage, Children, and Personal Life

Beyond his career(s) as a printer, bookseller, banker, treasurer, and inventor, Thomas Fowler was also a family man with a personal life.


Thomas Fowler married Mary Copp on February 21st, 1813.


Fowler and his wife Mary had 11 children between 1813 and his death in 1843. Sadly, as was often the case at the time, many of these nearly dozen Fowler children died young and never made it to adulthood. However, the ones that did saw nearly as much success as their father. Take Caroline, for example, who had already become a notable illustrator by the time she was eight. 


At the relatively young age of 66, Fowler succumbed to dropsy of the chest. While this sounds like a strange cause of death to us today, dropsy was the 1800’s term for edema (also known as swelling). There are all sorts of causes for this, ranging from heart issues to kidney problems and a slew of other factors in between.

Thomas Fowler’s Published Works

A Description of the Patent Thermosiphon (1829)

A formal explanation of how his original thermosiphon worked.

Tables for Facilitating Arithmetical Calculations in Poor Law Unions (1838)

A formal explanation of how his binary and tertiary tables worked.

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