existing conventions between the states, conferring more extended powers or containing other stipulations not contrary to the convention. {Sidenote: Final protocol} On the exchange of ratifications September 5, 1887, a final protocol was agreed upon, extending article IV to cover photographs in those countries whose domestic legislation or treaty arrangements permitted such protection; extending article IX to choregraphic works in countries in which they were covered by domestic legislation; explicitly excepting mechanical music reproductions from protection; and specifically referring to domestic or treaty arrangements, the protection afforded by article XIV to existing works not fallen into the public domain. The final protocol also provided for the organization of the international office under regulation by the Swiss Confederation, for French as the official language, for the allotment of expenses among the countries, and for other administrative details. {Sidenote: Ratification in 1887} The Berne convention, as signed in that city September 9, 1886, by the representatives of ten nations, Great Britain, Germany, Belgium, Spain, France, Haiti, Italy, Switzerland, Tunis and Liberia, was ratified in the same city September 5, 1887, by exchange of ratifications on the part of all these powers except Liberia, and became effective December 5, 1887. The French acceptance included Algiers and the other French colonies, the Spanish acceptance all Spanish colonies, and the British acceptance, India, Canada and Newfoundland, the South African and the Australian colonies. To these powers were later added Luxemburg (1888), Monaco (1889), Montenegro (1893), which however withdrew in 1900, Norway (1896), Japan (1899), Denmark (1903), Sweden (1904), and Great Britain's new colonies, the Transvaal and Orange Free State (1903), leaving three nations of first rank outside the Union, _i. e._, Austria-Hungary, Russia, and the United States, aside from the South American countries later associated in the Pan American Union. {Sidenote: Paris conference, 1896} The revision of the Berne convention provided for in art. XVII, which was to be made according to the final protocol at a conference at Paris to be called by the French government within from four to six years, was not actually undertaken until 1896. When the signatory powers met in conference at Paris, April 15 to May 4, 1896, they adopted an "additional act," of four articles, which besides making verbal amendments for clarification, substantially modified articles II, III, V, VII, XII, XX, of the Berne convention and the first and fourth numbers of the final protocol; and issued also an "interpretative declaration" as to both the Berne convention and the final protocol, the additional act and the interpretative declaration being sometimes cited together as "the Paris acts." {Sidenote: Paris Additional Act}