Births on April 22

Wilhelm Schickard, German astronomer and mathematician (d. 1635)

Wilhelm Schickard, born on April 22, 1592, and passing on October 24, 1635, was a distinguished German polymath of the Renaissance era, serving as a professor of Hebrew and astronomy at the University of Tübingen. His broad intellectual pursuits encompassed mathematics, optics, cartography, and even the design of early mechanical devices. However, it was not until the second half of the 20th century that Schickard garnered widespread attention, largely due to the work of Franz Hammer, a biographer who, alongside Max Caspar, extensively studied the life of Johannes Kepler. Hammer brought to light a fascinating discovery that challenged the established history of computing.

According to Hammer, drawings of what he termed a "calculating clock" were unearthed in two previously obscure letters written by Schickard to his renowned contemporary, Johannes Kepler, in 1623 and 1624. These meticulously detailed designs for a mechanical calculator appeared to predate the public release of Blaise Pascal's celebrated "Pascaline" by a remarkable twenty years. Hammer vehemently argued that because these critical letters had supposedly remained lost for three centuries, Blaise Pascal had, for all that time, been erroneously celebrated as the sole inventor of the mechanical calculator, suggesting that history needed a significant re-evaluation.

Evaluating Schickard's "Calculating Clock"

The re-discovery sparked considerable excitement and scholarly debate, prompting a more rigorous examination of Schickard's claims and his machine's capabilities. However, a closer, more critical analysis of the historical record revealed a nuanced picture that challenged Hammer's initial assertions. Far from being entirely lost, evidence emerged suggesting that Schickard's drawings had, in fact, been published periodically, dating back to at least 1718, long before the 20th-century "rediscovery." This finding directly contradicted the premise that the letters had been hidden for three hundred years, thus diminishing the claim that Pascal's recognition was solely due to their obscurity.

Furthermore, careful technical scrutiny of Schickard's design revealed significant practical limitations. The machine, as depicted in the drawings, was found to be incomplete, requiring additional wheels, springs, and other components to function. Crucially, its design incorporated a simple "single tooth carry" mechanism, a system that proved inherently unreliable and prone to malfunction when applied to the complexities of calculating clocks, especially during multi-digit operations. This mechanical flaw suggested that even if constructed, the device would likely have struggled with accurate and consistent operation.

Innovative Design, Practical Challenges

Despite these functional hurdles, Schickard's machine was undoubtedly a groundbreaking concept. It stood as one of the very first documented designs for a direct-entry calculating machine in the 17th century, paving the way for similar endeavors by other brilliant minds of the era, including Blaise Pascal, Tito Burattini, Samuel Morland, and René Grillet. Schickard's design was particularly notable for its ingenious integration of two distinct functionalities: an array of rotated Napier's rods, cleverly used for multiplication, combined with the first known design for an adding machine. This adding component was operated by simply rotating knobs for input, with a register of rotated numbers displayed in windows for output. This combination was a true innovation, aiming to streamline complex arithmetic operations.

Legacy and Influence: A Complex Debate

Historian René Taton has argued that, despite its conceptual brilliance, Schickard's work had no direct or measurable impact on the subsequent development of mechanical calculators. This perspective often highlights the practical non-existence of a fully functioning prototype and the lack of widespread dissemination of his ideas during his lifetime. The imperfect nature of the "single tooth carry" mechanism, a fundamental challenge for many early mechanical calculators, might also have contributed to this perceived lack of influence.

However, the debate over what truly constitutes a "mechanical calculator" and the scope of "influence" is ongoing. While Schickard's work may not have directly inspired the likes of Pascal or Leibniz, it undeniably pioneered a conceptual pathway for integrating multiplication aids with adding mechanisms. Later devices, such as Samuel Morland's multiplying and adding instruments (used in conjunction), Caspar Schott's Cistula, René Grillet's machine arithmétique, and Claude Perrault's rhabdologique towards the end of the 17th century, and even the Bamberger Omega developed in the early 20th century, arguably followed a similar conceptual trajectory. They explored the same innovative path championed by Schickard: a groundbreaking combination of a form of Napier's rods and an adding machine designed specifically to assist multiplication. Thus, while not necessarily a direct lineage of mechanical design, Schickard's pioneering vision for integrated computational tools certainly marked an important, albeit complex, chapter in the early history of computing.

Frequently Asked Questions (FAQs)

Who was Wilhelm Schickard?

Wilhelm Schickard (1592–1635) was a German polymath, professor of Hebrew and astronomy, and a pioneer in various fields, including cartography and mechanical devices. He is best known for his conceptual design of an early calculating machine.

What was Schickard's "calculating clock"?

The "calculating clock" refers to Schickard's design for a mechanical calculator, detailed in letters to Johannes Kepler in 1623 and 1624. It ingeniously combined Napier's rods for multiplication with an adding machine operated by rotating knobs.

Why was its "rediscovery" significant?

The discovery of Schickard's designs in the 20th century, particularly by Franz Hammer, suggested that his machine predated Blaise Pascal's calculator by two decades, thus challenging the long-held belief that Pascal invented the first mechanical calculator.

Did Schickard invent the first working mechanical calculator?

While Schickard designed a sophisticated calculating machine, it was found to be incomplete and had mechanical flaws, particularly with its "single tooth carry" mechanism, meaning it likely never functioned reliably or fully as depicted. The drawings were published, but a fully operational and documented prototype from his time is not known.

What were the limitations of Schickard's machine?

Technical analysis revealed that Schickard's machine was incomplete and would have required additional components (wheels and springs). More critically, its core single-tooth carry mechanism was fundamentally flawed for reliable use in complex calculating operations, making it prone to errors.

Did Schickard's work influence later inventors?

While some historians argue there was no direct impact on subsequent major inventions like Pascal's, Schickard's conceptual integration of Napier's rods with an adding machine set a precedent. Later devices by inventors like Morland, Schott, Grillet, and even the 20th-century Bamberger Omega, explored similar paths of combining multiplication aids with adding mechanisms, suggesting a conceptual, if not direct mechanical, lineage from Schickard's pioneering ideas.