Hero background

All auctions / Watches & Clocks / 1868 C.H. Webb "The Adder" Calculator

19d 10hUSWeiss Auctions

1868 C.H. Webb "The Adder" Calculator

1868 C.H. Webb "The Adder" Calculator

C.H. Webb "The Adder," an early two-disc brass mechanical adding machine mounted on a shaped wooden base. Manufactured by C.H. Webb, New York, and marked "THE ADDER PAT'D MARCH 10TH 1868." The device consists of two interconnected metal dials, with the larger wheel numbered 0 to 99 and the smaller wheel numbered 0 to 49 representing hundreds. The mechanism incorporates an automatic tens-carry. Calculations are performed by rotating the dials with a stylus inserted into the holes around each dial; stylus is not included. Serial numbered 5371 on the reverse. Overall approx. 4.75" x 6.75". Brass face exhibits age-related patina, oxidation, spotting, scratches and surface wear; wooden backing shows general wear. Appears to be missing three small screws along the brass edges. Estimate $200 - $300

Estimate:$200

To the auction

View all items fromWeiss AuctionsorWatches & Clocks

Estimate:

$200

To the auction

Similar items

Auction results for similar items

VÄGGUR, Swedish Modern, 1940-tal, fanerad med bl.a. mahogny och rotfaner
Sold
ARMBANDSUR, Seiko, stål.
Sold

ARMBANDSUR, Seiko, stål.

10/22/2026

Helsingborgs Auktionskammare
SE

$30.2

Est: $40.44

Details

Upcoming auctions

Masterpieces of Modern Art: Constructivism & Suprematism
Masterpieces of Modern Art: Constructivism & Suprematism auction house logo

NOV 8 | 1:00 PM

Masterpieces of Modern Art: Constructivism & Suprematism

Best of Auktion
Best of Auktion auction house logo

OCT 31 | 4:00 PM

Best of Auktion

Jewellery and Watches
Jewellery and Watches auction house logo

OCT 27 | 4:00 PM

Jewellery and Watches

Bring your auction to collectors worldwide!

Get listed now