Markham is often credited as one of the earliest writers in English on the subject of Swiss Hallmarks and Maker’s Marks. In this case he incorrectly translated (or interpreted) Helvetia as Juno.
Google Translation from the (slightly modified) French gives:
Federal law concerning the control and guarantee of title of gold and silver works. (From December 23, 1880.)
THE FEDERAL ASSEMBLY of the SWISS CONFEDERATION, pursuant to Articles 31(c) and 64 of the federal constitution; having regard to the message of the Federal Council of November 28, 1879, decrees:
Article 1 . The manufacture and sale of gold and silver works are subject to the following provisions.
A. For watch cases bearing, in number or in figures, in full or in abbreviated form, one of the following indications or any other relevant information, namely:
18 karats or 750 thousandths and above,
14 karats or 583 thousandths;
875 thousandths and above,
the control is obligatory; they must be equipped, following the requirements of the Federal Regulations, with the federally controlled hallmark, unless they carry the official hallmark, or recognized equivalent, of another state.
These federally controlled hallmarks are reproduced below:
Notice that the “X” indicates the location where the distinctive symbol of the assay office would appear. These would have been similar to the following chart.
The Federal Act of 23 December 1880 on “the Assaying and Guarantee of the Fineness of Gold and Silver Articles” was repealed and superceded by the Federal Act on the Control of the Trade in Precious Metals and Precious Metal Articles (Precious Metals Control Act, PMCA) of 20 June 1933.
See 1995 – Current for more information.