A second conference for revision was called in 1908 by the German government, and met at Berlin October 14 to November 14, resulting in the signature on November 13, 1908, of a revised convention continuing or reconstituting the International Copyright Union and replacing by substitution the Berne convention and Paris acts in those states accepting it by ratification. To this conference the German government invited not only the signatory powers of the Union, then fifteen,--Belgium, Denmark (which had acceded to the Union in 1903), France, Germany, Great Britain, Haiti, Italy, Japan (1899), Luxemburg, Monaco, Norway, Spain, Sweden (1904), Switzerland, and Tunis; but also non-unionist countries, of which representatives were sent from twenty countries,--Greece, Holland, Portugal, Roumania and Russia, China, Persia and Siam, Liberia, the United States of America, Mexico, Guatemala and Nicaragua, Argentina, Chile, Colombia, Ecuador, Peru, Uruguay and Venezuela. The working committees were made up exclusively from representatives of the signatory powers, only these countries participating in the votes; active participation otherwise was confined to representatives of countries expecting to become signatory powers, Holland and Russia, while the other participants acted as observing representatives or supplied information on request. {Sidenote: United States' position} The United States delegate, Thorvald Solberg, Register of Copyrights, was present only to make observations and report, with no power to vote or to take part in the discussions, as stated in the remarks for which, on October 15, he was called upon, as follows: "In 1885 and 1886, at the conferences convened to draft the convention to create the International Union for the Protection of Literary and Artistic Property, the United States was represented. At that time, however, it was not deemed possible to send a plenipotentiary delegate, nor could such a representative be sent to attend the first conference of revision which met at Paris in 1896. "When the present conference was arranged for--early in the year--the German ambassador at Washington wrote to the Secretary of State of the United States a letter explaining the purpose and scope of this congress, inviting the Government of the United States to send delegates. The ambassador's letter explained that, in addition to delegates representing governments in the union, there would be present representatives from a considerable number of non-union nations. It was further stated that the attendance of such delegates from non-union countries would be greeted with special pleasure. This because of the conviction that whatever might be the final position taken by the non-union countries, or their laws, in relation to copyright, participation in the proceedings of this conference by such delegates from non-union countries would at all events contribute to arouse and increase interest in the Berne Union and its beneficial work.