*The Museum of HP Calculators*

# Adding Machines

Like slide rules, adding machines date back to the 17th century.
They started with simple
machines that could only add (and sometimes subtract.) Many were
rather tricky to use and could produce erroneous results with
untrained users.
Apparently, Wilhelm Schickard produced the first adding machine in
1623. Unfortunately, this one-of-kind machine was destroyed in a fire
and its existence remained unknown until recently.

Blaise Pascal
(re)invented an adding/subtracting machine in 1642 with no knowledge of
Shickard's machine.
Pascal made many of his machines and is therefore often thought of as the
original inventor.
His first machine was 14" x 5" x 3" and
had 8 digits.
The closest machine shown here to Pascal's is the
Addometer shown in the Simple Dial Or
Slide Adders section.

## More Adding Machine Information

Back to early models contents

Go on to the dial, slide and chain adders

Back to planimeters