Wood - Backed Webb Adder / Adding Machine
Item History & Price
| Reference Number: Avaluer:18833123 | Maker: Charles 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. The serial number of this one, stamped into the wood back, is B803. An improved, all-metal version was patented in 1889, and that all-metal Webb, and copies of it, are the most common version 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 other 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. Good, not great. The large dial works perfectly, and carries to the small dial effortlessly, thanks to its stored energy system for carry. I noticed that my stylus would catch on something while turning the large dial though a full circle, and to avoid that I had to not insert it completely. The Webb has very small holes for the stylus, requiring a stylus with quite a small point, but also one that will not penetrate too deeply. I borrowed a stylus from a small slide adder to test this Webb. While the small dial turns easily when the large dial carries, I could not make the small dial move with the stylus. I did not apply a large amount of force, but at least twice what should have been required. When carrying from the large dial, the small dial rotates so easily that you can’t feel it at the stylus, and it snaps into position perfectly. I am at a loss for why it can’t be turned manually.
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.
On Oct-08-19 at 19:06:08 PDT, seller added the following information:An owner of a wood-backed Webb Adder (thank you ratzb) has informed me that the reason the smaller dial won't turn with the stylus is because the release pushbutton for it is missing. Unlike the later, all-metal Webb Adders, the wood-backed ones required you to push a release button before the small dial could be turned. That pushbutton is simply a small thumbscrew that screws into the hole just above and to the left of the small dial's center screw in the first picture. To test this I borrowed the thumbscrew from another wood-backed Webb and tried it on this one. It worked, the small dial turned easily when the thumbscrew was pressed. I measured the thread: #3-48. I then went to the local Ace Hardware to find an 1860s-ish brass thumbscrew with a #3-48 thread. I came home with the only #3-48 screw in the store: a stainless steel machine screw. It works, it is completely functional although aesthetically challenged.
I have added three pictures that show, a) how the screw should look vs. how the stainless steel replacement looks, b) how the screws look installed in the adder, and c) the instructions which explain how the screw/pushbutton is used. These instructions came from a different adder, but if you want a scan of them just let me know. I will print out a copy and include it with this adder. I have returned the brass thumbscrew to the adder I borrowed it from; this adder will be supplied with Ace Hardware's very finest stainless steel replacement.
This Webb Adder is in good condition for its age. Good, not great. The large dial works perfectly, and carries to the small dial effortlessly, thanks to its stored energy system for carry. I noticed that my stylus would catch on something while turning the large dial though a full circle, and to avoid that I had to not insert it completely. The Webb has very small holes for the stylus, requiring a stylus with quite a small point, but also one that will not penetrate too deeply. I borrowed a stylus from a small slide adder to test this Webb. While the small dial turns easily when the large dial carries, I could not make the small dial move with the stylus. I did not apply a large amount of force, but at least twice what should have been required. When carrying from the large dial, the small dial rotates so easily that you can’t feel it at the stylus, and it snaps into position perfectly. I am at a loss for why it can’t be turned manually.
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.
On Oct-08-19 at 19:06:08 PDT, seller added the following information:An owner of a wood-backed Webb Adder (thank you ratzb) has informed me that the reason the smaller dial won't turn with the stylus is because the release pushbutton for it is missing. Unlike the later, all-metal Webb Adders, the wood-backed ones required you to push a release button before the small dial could be turned. That pushbutton is simply a small thumbscrew that screws into the hole just above and to the left of the small dial's center screw in the first picture. To test this I borrowed the thumbscrew from another wood-backed Webb and tried it on this one. It worked, the small dial turned easily when the thumbscrew was pressed. I measured the thread: #3-48. I then went to the local Ace Hardware to find an 1860s-ish brass thumbscrew with a #3-48 thread. I came home with the only #3-48 screw in the store: a stainless steel machine screw. It works, it is completely functional although aesthetically challenged.
I have added three pictures that show, a) how the screw should look vs. how the stainless steel replacement looks, b) how the screws look installed in the adder, and c) the instructions which explain how the screw/pushbutton is used. These instructions came from a different adder, but if you want a scan of them just let me know. I will print out a copy and include it with this adder. I have returned the brass thumbscrew to the adder I borrowed it from; this adder will be supplied with Ace Hardware's very finest stainless steel replacement.
