Wood - Backed Webb Adder / Adding Machine
Item History & Price
| Reference Number: Avaluer:15587172 | Maker: C. H. Webb |
The Webb Adder was first patented in March 1868 by Charles H. Webb. This wood-backed early version of the adder is based on that original patent. I cannot find a serial number on this one. An improved, all-metal version was patented in 1889, and that all-metal Webb, and copies of it, are the most common versions seen now. The Webb is a column adder, meant to add numbers column by column, just like you were taught in school. What the Webb has over most othe...r column adders is that it can add three columns at a time, thanks to having two dials, one of which handles numbers from 1-99, and the other for the third column. This would have been a significant improvement in speed over single-column adders. The Webb can keep adding up to a maximum total of 4999.
This Webb Adder is in good condition for its age. The large dial turns stiffly, and the whole mechanism feels “dry”, metal on metal. The small dial also turns stiffly. Carry does not work. You can turn the large dial through several revolutions but the small dial does not increment. The Webb requires quite a sharp stylus because the holes are so small. If your stylus has a long, narrow taper, it will probably extend far enough through the large disc to catch on something inside when it rotates. If the large wheel stops turning, don’t assume the mechanism has locked up. More likely the point of the stylus has caught on something. Pull the stylus out, move it to a different hole, and try again. In my experience all wood-backed Webbs do this, but the metal ones don’t. One other thing, the lettering on this Webb is not stamped very deeply, and it isn’t filled in with any sort of pigment, so it is nearly the same color as the brass around it. I had to resort to low-angle lighting just to make it readable in a few of the pictures.
This adder 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. Starting 01 Oct 2019, Ebay is collecting sales tax for the 34 states that are charging sales tax on Internet purchases.
Shipping will be by USPS Priority Mail. Shipping charges will be somewhat higher for destinations outside the USA.
Oughtred11 is going on winter hiatus now, but we will be back early in the new year. Merry Christmas and Happy New Year from the Oughtred Society.
This Webb Adder is in good condition for its age. The large dial turns stiffly, and the whole mechanism feels “dry”, metal on metal. The small dial also turns stiffly. Carry does not work. You can turn the large dial through several revolutions but the small dial does not increment. The Webb requires quite a sharp stylus because the holes are so small. If your stylus has a long, narrow taper, it will probably extend far enough through the large disc to catch on something inside when it rotates. If the large wheel stops turning, don’t assume the mechanism has locked up. More likely the point of the stylus has caught on something. Pull the stylus out, move it to a different hole, and try again. In my experience all wood-backed Webbs do this, but the metal ones don’t. One other thing, the lettering on this Webb is not stamped very deeply, and it isn’t filled in with any sort of pigment, so it is nearly the same color as the brass around it. I had to resort to low-angle lighting just to make it readable in a few of the pictures.
This adder 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. Starting 01 Oct 2019, Ebay is collecting sales tax for the 34 states that are charging sales tax on Internet purchases.
Shipping will be by USPS Priority Mail. Shipping charges will be somewhat higher for destinations outside the USA.
Oughtred11 is going on winter hiatus now, but we will be back early in the new year. Merry Christmas and Happy New Year from the Oughtred Society.
