On collecting slide rules

The collection of slide rules and other mechanical calculating devices is fuelled by the desire to stop for a moment in the surge of our computerised lives, and to contemplate such masterful relics of a byegone age, when craftsmanship was an honour as much as it was a trade, and when the users of the fine precision instruments and a logical and broader understanding of mathematics than the button-pushing masses of today.

I have decided to present two of the gems of my collection of slide rules and mechanical calculating devices to the Web World, in the hope that these images will portray some of the qualities of these fine instruments (instruments so precise thay were able to perform the calculations which set man on the moon)

The Castell Addiator

A slide rule on the front, an adding machine on the back, this rare and unusual pocket calculator is the essence of German quality, having a considerable weight and giving the impression of rugged durabilty. Bought by me at a local junk shop for pennies, I have never before or since seen a similar slide rule, and know nothing about this model except it seems to have an unusual currency scale on the reverse of the slide: perhaps this was the forerunner of the modern financial calculator? Any comments in this respect would be appreciated!



The Rapid-Calcolo

Once again, a bargain basement find, including documentation and original carrying case. Who knows anything about this so-very-Italian mechanical pocket adding machine. It seems to have jumped out of a pre-war Italian film, complete with images of the young ingeniori cycling home on the streets of Rome, with his Rapid-Calcolo resplendant in the pocket of his jacket. Any more serious contributions to the age and origin of this, the favourite exhibit in my collection, would be gratefully received!

Castell Addiator

Castell Addiator