CIRCA 1845

細節

A large diameter Loseby mercurial balance
Circa 1845
Cut bimetallic balance with Loseby's two glass mercurial arms each secured to the outer ends of the long segment of the balance rim, cylindrical heat compensation weights, mean time screws, blued steel helical balance spring, balance staff mounted between top and bottom pivot jewels set in U-shaped frame, in a later exbibition brass drum glazed top and bottom, the whole mounted in adjustable white metal frame above a turned mahogany base
40 mm. diam. of balance, 120 mm. overall height

拍品專文

Edward Thomas Loseby, (1817-1890) was born in Leicester, the son of a watchmaker, he apprenticed to Rotherhams of Coventry before joining his father's business and then setting up in 44 Gerrard Street, Islington as a chronometer maker.
Loseby designed his mercurial balance to eliminate middle temperature error and developed it from 1840 to 1852.
The Astronomer Royal, G.B. Airy apparently gave Loseby the mis-guided impression that if he could come close or actually solve middle temperature error then he would receive an award from the Lord Commissioners of the Admiralty. Amazingly between 1846 and 1852 Loseby came first no less than six times at the Annual Greenwich Trials but in 1852, having won it for the sixth time and receiving no payment whatsoever he retired back to Leicester!