About the Seth Thomas “Baso” Clock
The Seth Thomas “Baso” clock, a unique tambour piece from 1917, showcases an uncommon case style that sets it apart from other collectibles of its era. This particular model, boasting a mahogany adamantine finish, has survived with minor battle scars from its journey to Texas. Three to four small nicks have been discreetly addressed using a red mahogany pencil stain, making their detection somewhat challenging.
The clock’s 8-day movement operates robustly, chiming the half hours on a cathedral bell. The dial and convex glass are both convex in shape, as indicated by the catalogs, which describe it as a “New convex 5-inch dial”. Though beginning to flake slightly in the lower half, this dial is characteristic of Seth Thomas’ traditional design aesthetic.
The movement bears the ST logo and the number “89”, identifying it as Ly-Seth Thomas #1257. This clock offers a fascinating blend of rarity and classic craftsmanship, making it an intriguing addition to any horological collection.
Auction Records and Price History
The following 1 auction record(s) show actual sale prices for the Seth Thomas “Baso” model clock. Prices vary based on condition, originality, and current market demand. Search for more records on AntiqueClocksPriceGuide.com.

Seth Thomas tambour with a mahogany adamantine finish, “Baso”, ca 1917.
The case style is not one we see often, in fact, I never have. It took a hit or two in the ride from Texas. I touched 3-4 small nicks with a red mahogany pencil stain and now the nicks are hard to find. The 8 day movement is running up a storm, striking the half hours on a cathedral bell. Convex dial and convex glass. The catalogs call the dial a “New convex 5-inch dial”. It is different, I guess paint on metal, but typical of Seth Thomas dials, it is beginning to flake in the lower half. Movement is signed with the ST logo and “89”. Ly-Seth Thomas #1257.
Sold: $0 unsold | Date: June, 2004 | Source: Horton’s Antique Clocks