1. Gottfried Wilhelm Leibniz and his calculating machine
report by Torsten Brandes

2. Chapter 1
Construction of mechanical calculating machines

3. Structure of a mechanical calculating machine
counting mechanism
two counting wheels

4. counting mechanism Every counting wheel represents a digit.
By rotating in positive direction it is able to add, by rotating in negative direction it is able to subtract.
If the capacity of a digit is exceeded, a carry occurs.
The carry has to be handed over the next digit.

5. counting mechanism S – lever Zi – toothed wheel
dealing with the carry between two digits

6. Chapter 2: calculating machines bevore and after Leibniz
1623
Wilhelm Schickard developes a calculating machine for all the four basic
arithmetic operations. It helped Johann Kepler to calculate planet‘s orbits.
1641
Blaise Pascal developes an adding- and subtracting machine to maintain
his father, who worked as a taxman.
Leibniz is working on his calculator. 
1774
Philipp Matthäus Hahn ( ) contructed the first solid machine.

7. Leibniz‘ calculating machine.
Leibniz began in the 1670 to deal with the topic.
He intended to construct a machine which could perform the four basic arithmetic operations automatically.
There where four machines at all. One (the last one) is preserved.

8. stepped drum
A configuration of staggered teeth. The toothed wheel can be turned 0 to 9 teeth, depending of the position of this wheel.

9. four basic operations performing machine by Leibniz

10. Skizze H – crank K – crank for arithmetic shift rotation counter
drawing: W. Jordan
H – crank
K – crank for arithmetic shift
rotation counter

11. Functionality Addition: partitioning in two tacts
Addition digit by digit, saving the occuring carries with a toothed wheel.
Adding the saved carries to the given sums, calculated before.

13. Subtraction. Similar to adding.
The orientation of rotating the crank has to be turned.

15. Multiplication (excampel)
was possible by interated additions
32.448*75
Input of in the adjusting mechanism.
Input of 5 in the rotation counter.
Rotating the crank H once. The counting mechanism shows
Rotating the crank K. The adjusting mechanism is shifted one digit left.
Input of 7 in the rotation counter.
Rotating the crank H once. The counting mechanism shows