Until this time all double rifles had external hammers whose fall struck the mechanism which fired the cartridge, however attempts to remove them were well under way. The first "hammerless" action of significance was invented by Thomas Murcott in 1871, known as "The Mousetrap", it was a complex design but it sold in significant numbers. In 1875, Westley Richards employees William Anson and John Deeley patented the "Anson & Deeley" hammerless boxlock action, and in 1878 the Birmingham gunmakers W&C Scott & Son invented the basic sidelock action which was so successful it was immediately adopted by Holland & Holland.