This is a Triumphator calculating machine. It belonged to my late father-in-law, who was born in 1916. Exactly when it was made, we are not certain, but they date back to around 1910, I'm told. This one has a sticker on the bottom with the name of a supplier in Stockholm. As far as my husband can remember, his father bought this in Stockholm circa 1965.
It has a serial number on it. Why do I find that quaint?
It really works. It adds, subtracts, multiplies and divides.
It weighs a mere 5.6kg, according to my bathroom scale, so there is no way you could call this a pocket calculator!
It may well be worth a fair amount of money, but there is no way my husband, an IT (and logistics) manager, is going to part with it! It's an early computer, after all! I suspect few people realise that the history of computing stretches back a lot further than the Enigma machine.