May 8, 1872 134,868 Electro Magnetic adjusters .
"Edison, His Life and Inventions"
Frank Lewis Dyer and Thomas Commerford Martin
Sir William Thomson, one of the latest and perhaps the most successful of modern compass adjusters, when he exhibited his apparatus in 1878 before a distinguished meeting in London, remarked that within the last ten years the application of Sir George Airy's method had become universal, not only in the merchant service, but in the navies of this and other countries, and added-The compass and the binnacles before you are designed to thoroughly carry out in practical navigation the Astronomer Royal's principles.
"Autobiography of Sir George Biddell Airy"
George Biddell Airy