In Brief: Your Overview of This Revolutionary Adding Device
As early as the 1600s, innovators sought to mechanize mathematical calculations through clever mechanisms. But as you know, pencil and paper remained the dominant daily tool for addition and subtraction all the way into the 20th century. The Centigraph Adding Machine stands out in history as one of the first commercially viable appliances to automate and accelerate this fundamental office task.
In this 3000+ word guide, you‘ll discover the full background on this pioneering achievement. We‘ll explore when it was patented, how it worked, who invented it, why it was important, and how long it stuck around. You‘ll learn about coiled springs and rotating number discs, Atlanta manufacturers and San Francisco dreamers.
By the end, you‘ll appreciate how the Centigraph Adding Machine helped pave the way for modern accounting computers and calculators. The dual rotating disc design endures as an icon of Innovation. So let‘s dig in to its history and inner workings!
Invention and Inventor
The original inventor of the Centigraph was Arthur Ewing Shattuck (1854-1903), an entrepreneur and inventor from San Fransisco.
As a county and court clerk in his 20s, Shattuck witnessed the daily tedium of manual number-crunching. Slide rules, abacuses, and counting boards existed – but required full attention and still took considerable time for long computations.
In 1880 at just 26 years old, Shattuck conceived the first ideas for the Centigraph Adding Machine – a mechanical device aimed to automate calculations with minimal supervision. Rather than relying on the human brain, clever gear mechanisms would carry out the math.
This early vision would take considerable refinement before becoming reality. But Shattuck was no stranger to innovation in calculation tools. In fact, he secured multiple patents over the next decade for mechanical adding contraptions, including early "chain adding" concepts with his business partner Charles Thorn.
However, his collaboration with inventor Brainard Smith is what finally produced the Centigraph. Let‘s look closer at how it actually worked.
Key Components and Operation
The key innovation of the Centigraph Adding Machine was its integration of two rotating discs marked with numeric position scales:
- One disc featured 100 engraved positions along the outer edge, allowing representation of digits from 1-99.
- The second disc had just 20 positions – but when integrated, allowed tracking hundreds place values up to 599.
The machine itself featured five mechanical digit keys for input labelled 1, 2, 3, 4 and 5. Pressing these would rotate the corresponding discs precisely by one position, aligning the next digit value with an output display window.
To input two-digit numbers, the user simply pressed the appropriate keys simultaneously. For example, hitting the 2 and 4 keys together would rotate and show 26 in the display. More combinations allowed representation of any number up to 99.
The true magic was in the automatic addition as values were entered. As the hundreds and tens discs independently rotated, they interfaced through a clever coiled spring mechanism that computed sums mechanically. So entering 26 then 30 would accurately display 56 in the window once both were input. At any point, the current total was visible and required no mental tracking.
Once done entering values, the user could reset the position back to 0 with a lever arm in preparation for the next series of numbers. Weighing over 50 pounds, the Centigraph had substantial heft and was far from portable. But as a desktop model, its efficient mechanical adding capabilities finally outpaced tedious paper and pencil methods.
Patenting, Manufacturing and Adoption
After securing his fourth US patent in 1891 covering the dual-disc Centigraph model, Shattuck quickly found interest in licensing production rights.
The American Adding Machine Company (AAMC), an established firm in Atlanta, Georgia acquired the patents and began mass manufacturing Centigraph models at scale starting in 1902. The first known advertisement showcasing the device appeared within a year in a 1903 volume of "The Atanta Constitution" daily newspaper.
Other prominent early manufacturers of Centigraph Adding Machines included:
| Company | Location | Year Started |
|---|---|---|
| American Adding Machine Co. | Atlanta, GA | 1902 |
| The Centigraph Company | New York City, NY | 1890 |
| Jones Adding Machine Co. | Stamford CT | 1915 |
Within a decade, the Centigraph became a relatively ubiquitous office machine. Leading business journals including "The Economist" and "Bankers Monthly" carried full-page ads touting its utility for payroll, accounting, banking and more. Its unique dual-rotating disc mechanism made it stand out from alternatives of the era.
By 1910, variants like 10-key input models were available from multiple vendors, allowing more complex calculations. As demand grew globally, the Centigraph could be found hard at work balancing the books and ledgers of America‘s booming new corporations.
Gradual Decline and Enduring Legacy
By the early 1960s, the release of the first affordable electronic calculators started challenging traditional mechanical adding machines. Though new Centigraph variants added advanced printing capabilities, the pace of digital disruption accelerated through the 1970s. Spreadsheet software and personal computers eventually rendered devices like the Centigraph obsolete for most businesses by 1985.
Today, over 130 years since inventor Arthur Shattuck first envisioned that coiled spring mechanism, the Centigraph remains appreciated as a pioneering innovation. It helped catalyze the automation of routine arithmetic calculations in offices everywhere. The iconic rotating discs live on as a representation of additive machines that powered commerce through the 20th century‘s early boom.
Arthur E. Shattuck: Prolific Innovator
While the Centigraph was Arthur E. Shattuck‘s most famous contribution, his creative spirit extended far beyond. Throughout his career, he secured four US patents and one Canadian patent covering innovative calculating devices and methodologies:
- 1882 – Patent #268135 detailing early 10-key "chain adding" machine with partner Charles Thorn
- 1886 – Patent #349459 for improved 20-key rotational chain adder with Thorn
- 1887 – Patent #363972 for 5-key single column adder with Brainard Smith
- 1891 – Patent #453778 covering the seminal dual-disc Centigraph Adding Machine
Shattuck overcame substantial financial troubles starting out. But his breakthrough Centigraph concept brought wide fortune and acclaim later in life. Tragically, he died relatively young in 1903 at just 49 years old.
But in that short window, Shattuck unrelentingly pursued clever solutions to amplify human mathematical capacities. Though other inventors paved the way, his Centigraph unlocked the true promise of automated computation on every office desk. More than just a machine, it signified the enduring power of human creativity.
Over a century later, his dual disc legacy persists as an symbol of American ingenuity. Next time you effortlessly add a column of numbers on your computer or phone, take a moment to appreciate innovators like Arthur Ewing Shattuck!
