Calculating tools
Leonardo da Vinci, John Neper,
Wilhelm Shickard
Leonardo da Vinci (1452-1519)
Leonardo da Vinci was remarkable painter, engineer, anatomist, architect, sculptor, musician, etc. He produced thousands of
pages of perfectly illustrated notes, sketches and designs.
A sketch from Codex Madrid
was founded in Biblioteca Nacional de España (National Library of Spain) in Madrid in 1967.
(take into account, that in this case Leonardo, as in many of his writings, writes laterally inverted from right to left!).
Principle of operation
A device sketched here is for addition and substruction.
The gear wheels in the figure are numerated as follows: the
small wheels are numerated with 1, while the bigger wheels are numerated with 10.
For more informations see: https://history-computer.com/MechanicalCalculators/Pioneers/Leonardo.html
The replica of the Leonardo's machine, built
by Dr. Guatelli
John Napier (1550-1617)
Seeing there is nothing that is so
troublesome to mathematical practice…
than the multiplications, divisions,
square and cubical extractions of great numbers, which besides the tedious expense of time are... subject to many slippery errors, I began therefore to consider [how] I might remove those hindrances.
Excerpt from A Description of the Wonderful Canon of Logarithms
Lord of Merchiston, Scotland
Napier’s bones
Napier invented several mechanical methods of simplifying and
speeding up multiplication, the most famous being special rods, later known as Napier's bones.
In the next centuries a lot of inventors tried to improve and facilitate the work with Napier's rods, starting from Wilhelm
Schickard.
For more informations see:
https://history-computer.com/CalculatingTools/NapiersBones.html
Principle of operation
Wilhelm Schickard (1592-1635)
Wilhelm Schickard was born in the small south German town Herrenberg, near Tübingen, and educated in the Protestant theological seminary in Tübingen. In 1631 he became a professor of
astronomy, mathematics and geodesy.
In 1617 he met the great astronomer Johann (Johannes) Kepler. From this moment on,
Schickard entered into close friendship and busy correspondence with Kepler until his death and made science investigations for him. He designed for Kepler a mechanical calculating machine
(Schickard referred to it as Rechen Uhr—
calculating meter or calculating clock), which proved to be the first mechanical calculating device ever created
Schickard’s calculating clock
Unfortunately, the machine, designed by Schickard around 1623, didn't
manage to survive to the present day.
Only 3 documents about this machine have been found till now—two letters from Schickard to Kepler, and a sketch of the machine with instructions to the mechanician.
The machine used wheels to additions and substractions and Napier’s bones to multiplications and divisions.
Replica of Schickard's machine
Wilhelm Schickard was one of the most reputable scientists of Germany of his time. The opinions for this universal
genius from his contemporaries are—the best astronomer in Germany after Kepler's death, the foremost Hebraist after the
death of the elder Buxtorf and one of the great geniuses of the century. He
succeeded to finish only a small part of his projects and books, being struck down in his prime.
In 1631 Schickard and his family was under threat of the battles of Thirty Years' War, which approached Tübingen. In 1635 he become sick of plague and die. He is only 42 years old.
