Welcome to my "Mechanical Calculator" web site.


Hundred fifty years ago the first attempts were made to produce "heavy machines" to assist in counting work. Those machines, which we know as mechanical calculators, have a lot of metal gearwheels and are designed to perform the basic operations of arithmetic only. This is hard to imagine, now we have so much nice electronic gadgets, like smart phones, where a calculator is only an app, or an additional feature.
The production of reliable machines, started end of the nineteen century. The first machines were manual driven. Each number, inputted by sliders or an matrix of keys, has to followed by pulling a handle or turning a crank. The calculating results are readable on numbered wheels, capped by windowed masks or printed as listing. 10key keyboards, made one hand operation possible. Over the years various calculation technologies were developed. The nineteen fifties and sixties, were their glory years.
Since the nineteen seventies, electronic components are successfully applied in calculators. This transition gave calculators much more functionality. It was "the" obvious directions the calculator- and the nascent computer industry developed and was heading to. The production of mechanical calculators was stopped world-wide.

The purpose of this web site:

This web site calls attention to these (electro)mechanical calculators and intends to:
- give information on the history / the mechanisms used, and the manufacturers
- prevent that these technological highlights will be forgotten and personally I like to
  keep some machines fully functional for next generations to come.
- provide the readers with information on restoration experiences.

How to navigate this website:

The Manufacturer menu items, to the left, brings you to pages with the following menu icons on top:

History A brief story of the manufacturer history.
cam Photos of a my collection of mechanical calculators. Where the focus is on the:
- beauty of the outside designs, illustrating the time they are build
- interiors, which play an important part in the calculation and restoration process.
book Machine specification and the restoration story

I am a single writer of this website, but I get a lot of "appreciated" inputs / feedback, via e-mail etc, from other collectors / web masters / readers etc . world wide. Please drop me an e-mail if you have comments, or tell me what you like or likes to see changed or added, on this website.

Best regards,
Wim Hasselo


The content of this web site may be used for non commercial publications. Publication in commercial media is only allowed with my prior given written permission and a readable link to this web site.

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