Early mechanical
calculators - Johann Christoph Schuster, 1820
Hahn's calculating
machine, improved model by Johann Christoph Schuster, protégé and son-in-law
of Philipp Mathius Hahn. (1795-1823)
Brass, partly gold-plated, steel, round enamel scales.
Built between 1805 to 1820.
Provenance: Grimme Calculating Machine Museum, Natalis & Co AG,
Braunschweig.Waldbauer Collection No. 2397 Lit.: The Braunschweig GNC
monthly magazineNovember/December 1925, Braunschweig: p. 524 with
illustration. Described there as follows: Hahn machine. Invention of the
pastor Philip Matthäus Hahn, Echterdingen, Germany
1774. Manufactured in 1805 to1820 by the watchmaker Joseph Christian
Schuster, Ansbach, who worked as a journeyman for Hahn from 1778-1780 and
later married her sister.
Shuster's calculator was one of the last of the highly individually
built and elaborately ornamented calculators of the pre-industrial era; it
has 1052 parts. Calculating machines of the 17th and 18th centuries are
extremely rare. There are in fact only ten calculating machines remaining
from that period, which are four species, that is can perform all four basic
operations of arithmetic, (addition, subtraction, multiplication and
division). During the baroque age there was neither a commercial nor a
scientific need for mechanical calculating machines. Tradesmen still
calculated using calculation boards, tables and reckoning counters. And in
the sciences, calculating methods were unknown or just beginning to be
developed. Thus, the clergyman Philipp Mathaus Hahn (1739-1790), Schuster's
mechanical master and brother-in-law, had built his calculating machines 'for
the propagation of the Gospel'.
At the time they were built, these calculating machines were not
used practically. They were destined for the curiosity cabinets; the 'Kunstkammer'
of princes and nobility. Some, such the gloriously decorated machine by
Johann Jackob Sauter could have no other purpose!
Schuster commenced his first calculating machine according to
Hahn’s design in 1789 (probably under the supervision of Hahn), and it was
completed in Uffenheim in 1792 (Hahn had died two years earlier), a twelve digit design, 10 billion capacity.
From 1805 Schuster developed his own calculating machine in Ansbach (four-species machine, relay roller principle), which is
also based on Hahn’s design but is more compact and easier to use.Its construction is basically the same as the first
machine, but it has an improvement on the setting mechanism, where the racks
are similar to Müller‘s
calculating machine from 1783, and are moved
using rotary knurled knobs that mesh with the rods
while showing their digital values in a separate aperture. This calculator
has a nine digit capacity, 100 million. It was
completed in 1820. A third calculator was discovered in 1993 and was dated
as being built between 1820 and 1822, it is identical to his second machine
except that it has a ten digit capacity, one thousand million or one
billion.
Johann Christoph Schuster was born on 8 October 1759 in
Westheim (Middle Franconia, Bavaria, Germany). He was the son of Lorentz Schuster
(died 1785), a local farmer, and Anna Elisabetha Fröhlich (died 1762).
In his youth he became enraptured with watches - as a thirteen year old he
is reported to have built a wooden clock, and subsequently to have repaired
watches successfully. Around 1777 he was bound
apprentice to Philipp Matthäus Hahn, a pastor and owner of
a mechanical workshop in Kornwestheim. Schuster remained in
Hahn’s workshop for two and a half years, then returned to his father’s
farm, but continued his occasions with machines, keeping a connection with
his mentor. In 1785 Schuster married Maria Katharina
Jacobina (1759–1812), a half-sister of Hahn. They had three sons (two of
them died early) and five daughters.
After his father’s death in 1785 Schuster took over
his farm and also opened in the village a workshop in which
he made clocks, sundials, earth and celestial globes, and
calculating machines. From 1786 he was a freelance
watchmaker, first in his native Westheim and then in
Uffenheim. Schuster moved to Ansbach in 1797 and became a
master member of the local watchmaker’s guild and received
permission to work as a “mechanic and watchmaker” in Ansbach,
Uffenheim, and Erlangen. He ran a workshop in Ansbach, the
seat of Hohenzollern princes (known as margraves), and
stayed there working as a mechanic and court watchmaker
until his death.
Besides the above-mentioned calculators, four other
masterpieces of Schuster survived to our time: two pocket
watches (now in Württembergisches Landesmuseum Stuttgart and
Stadtmuseum Ansbach) and two double globe
astronomical clocks (in
Mathematisch-Physikalischer Salon Dresden, and one in a private
collection).
Johann Christoph Schuster died on 7
September 1823 in Ansbach.
The watchmaker Jacob Auch (1765-1842) was, besides Johann Christoph
Schuster, the second mechanic of Philipp Matthaus Hahn that built
calculating machines of his own. Three of his adding machines remain - they
are in Stuttgart, Dresden and Leyden. Hahn is thought to have built four,
four species calculating machines.
The nine digits of the setting mechanism are operated with knurled
nuts, whereby the setting of a number can be checked in a control mechanism
with dials. The result mechanism and the revolution counter are located in
the central, rotating part of the machine, they are each ten digits. The
larger enameled dials belong to the result mechanism, and the smaller ones
to the revolution counter. The black and red digits in the result set are
intended for multiplication and division, respectively (red digits present
complementation to 9 of black digits, e.g. over black 5 is inscribed red
4).
This video with the use of computer aided design, shows the layout, components and function of the Schuster
calculator. Video demonstration using computer animation to show the
internal components as well as the functionality of the Johann Christoff
Schuster calculator made in 1820. The first four species calculator capable
of addition, subtraction, multiplication and division was invented by
Gottfried Leibniz in 1672. From that time through the time this artifact was
produced, about a dozen hand-built calculating machines were produced. Video
courtesy of the Arithmeum, Bonn, Germany.
This video demonstrates the Hahn calculator, however, other than the way
the operand in inputted (a sliding scale stick vs. the stick being operated
by a numbered thumbwheel), they both operate the same way.
Internal schematic of the Hahn design. Very similar to Shuster's.
Photo from the Grimme Calculating Machine Museum, Grimme, Natalis & Co
AG. A section of the museum c. 1925 showing several late 17th and early 18th
century calculators. photo c. 1890. The circled calculator is the
example described on this page. Then acquired by the Helmut Waldbauer
collection. Mr. Waldbauer was a dealer out of Vienna in typewriters and
calculators and built his collection over 55 years.
The company Grimme, Natalis & Company in Braunschweig was founded
in 1871 as a merger between Carl Gimme and Karl A, Nautalis,
both companies were engaged in the manufacture of sewing machines. In 1892
the company purchased the rights to manufacture pinwheel calculating
machines on the design of the Swede W. T. Odhner. Barrel, (pinwheel), calculating
machines were smaller, lighter, cheaper to make and easier to operate than
the Arithmomètre. Under the leadership of the
engineer Franz Trinks, later in 1892, they began manufacturing and improving a machine
called the Brunsviga. In 1927 the company
changed it's name to Brunsviga, reflecting their primary activity of the
manufacture of calculating machines under that trade mark name. Brunsviga
entered into an agreement with Olympia Werke AG of Wilhelmshaven (part of
the AEG group), in 1957 which led ultimately to the company being absorbed
into Olympia in 1959.
First Day Cover mailed in 2022, showing one of the three calculating
machines known to be made by Johann Schuster.