Victor Kullberg, A two-day marine chronometer with Kullberg's auxiliary compensation, no. 5254, circa 189

brass full plate movement with removable barrel bridge, one-piece balance cock, diamond endstone, helical palladium spring with two terminal curves, bi-metallic compensation balance with Kullberg's auxiliary compensation, reverse fusee with Harrison's maintaining power, silvered dial, wax-filled roman numerals, subsidiary seconds, sector for up-and-down, signed and numbered, gold hands, in brass gimbaled bowl, two-tier brass strung mahogany box with brass flush fitting handles and signed and numbered, ivory plaque.

Sold to the Royal Mail Steam Packet Company on January 7, 1893
Time Museum Inventory No. 609

Randall, cat. no. 94

Kullberg's auxiliary compensation is discontinuous; this means that it only affects the balance arm when it moves past a certain point and in one direction, in this case when it is in the extremes of cold. Apparently this worked well as it was employed on many chronometers after it was invented.

Victor Kullberg, an exceptional and inventive horologist, was born in Gothland, Sweden in 1824. In Old Clocks and Watches and their Makers, F.J.Britten says of Kullberg, "One of the most brilliant and successful horologists of the 19th Century." He worked first for Louis Urban Jurgensen in Copenhagen before coming to London in 1851 where he became a maker to The Admiralty. He was also awarded the Cross of the Legion of Honour.