DEMOS II Mechanical Calculator / Adding Machine
Item History & Price
| Reference Number: Avaluer:43913 | Maker: Theo Muggli |
The DEMOS calculator, made in Zurich, Switzerland by Theo Muggli, appeared in 1923, and due to an innovative mechanism of interlocking gears that could be implemented with stamped metal parts, it cost about half as much as competing pinwheel calculators. The box on this one looks awfully crude for a factory part, but also looks like more work than an individual would want to take on. I am unable to say whether the box is original or not, but I lean towards it being somethin...g an owner made himself. The calculator is solidly attached to the bottom of the box, which is probably why I can’t find a serial number – no doubt it is on the bottom of the calculator. As the picture of the bottom of the box shows, originally it had 4 wooden pegs for feet, but only one remains, and on one corner a large chunk of the wood is missing. It can spare it, that’s a thick chunk of wood on the bottom of the box. The first control I tried using was one of the clearing levers, and it was so tight, and the mechanism so thoroughly dry, that I did not try any more of them, afraid of doing more damage than good. There may or may not be a handle missing. There is what looks like a shaft a handle would attach to on the lower right side, but the picture in Martin appears to show that shaft without a handle. Note that shipping will be expensive as the Demos alone, without any box or padding, weighs 23.5 lbs.
This calculator is from the collection of Robert K. (“Bob”) Otnes, PhD, one of the founding members of the Oughtred Society and the original editor of the Journal of the Oughtred Society. It is being sold by the Oughtred Society on his behalf.
The Oughtred Society was founded in 1991 by a group of slide rule collectors and is dedicated to the preservation and history of slide rules and other calculating instruments. Membership is open to anyone. Further information about the Oughtred Society can be found at: http://www.oughtred.org/.
PayPal is the only accepted form of payment. Buyers within California will be charged 7.25% sales tax.
Shipping will be by USPS Priority Mail. Shipping charges will be somewhat higher for destinations outside the USA.
This calculator is from the collection of Robert K. (“Bob”) Otnes, PhD, one of the founding members of the Oughtred Society and the original editor of the Journal of the Oughtred Society. It is being sold by the Oughtred Society on his behalf.
The Oughtred Society was founded in 1991 by a group of slide rule collectors and is dedicated to the preservation and history of slide rules and other calculating instruments. Membership is open to anyone. Further information about the Oughtred Society can be found at: http://www.oughtred.org/.
PayPal is the only accepted form of payment. Buyers within California will be charged 7.25% sales tax.
Shipping will be by USPS Priority Mail. Shipping charges will be somewhat higher for destinations outside the USA.
