*S & N / THE SUN*

Close up of the total window and the columns of chains.

The value last entered was £23,450 00s 7 3/4d.

*S & N (Seidel and Naumann) / THE SUN*

Chain adding machine.

Illustrated is a Sterling currency version of the S & N chain adding machine. Manufactured by Seidel and Naumann of Dresden, Germany. It is labelled *"THE SUN"* for distribution in Britain by Taylor's Typewriter Co., London.

78 x 222 x 57 mm (3.1" x 8.75" x 2.25").

Designed for addition, this Sterling currency model has 9 chains and can add up to £99,999 19s 11d.

The chain links presented to the user have flattened tops marked with the numbers to be added. The special stylus is inserted in the slot in the chain just below the digit required to be added and moved
downwards to the horizontal bar. During this movement the numbers are added to the total shown in the window towards the top of the machine.

The chains latch in the position moved to and it is possible to check the number that
has been added. Pressing the lever at lower right allows the chains to spring back to their zero positions, ready for adding the next number.

The total can be cleared by pulling the lever at top right, forwards as far as it will
go and then releasing it.

Two moveable metal pointers aid in reading the columns.

Subtraction is possible with this model using complementary arithmatic.

Metric models were produced, and also ones including a subtraction mechanism. Some models have 13 chains rather than the 9 chains of
this model.

Note that this example appears to have a small cover missing which should be in place below the columns of chains.

Introduced in 1910, machines like this were sold for many years.

The adder in its fitted case, together with the stylus and operating instructions.

The label on the adder.

**Mechanical Calculators**

*Vintage Calculators *

Text & photographs copyright, except where stated otherwise, © Nigel Tout 2000-2024.