Double Standard

Collier's New Encyclopedia (1921)

in economics the phrase double standard is used to signify a double standard of monetary value. It implies the existence of what is known as the gold standard on the one hand, and the silver standard on the other. Wherever the double standard in its integrity is in use a creditor is bound to accept payment of any sum in coins of either of the metals, gold or BIMETALLISM. DOUBLE STARS and MULTIPLE STARS, stars which appear single to the naked eye, but in the telescope are resolved into two or more close together. There is no limit to the distance between these, but those whose components are more than 15" or 20" apart are not generally included in catalogues of double stars, and those whose distance is much less than 1" require telescopes of large aperture to separate them distinctly. The discovery and measurement of the position-angles and distances of the components of these objects form almost a distinct department of astronomical observation, to which many able astronomers have given nearly all their lives. These measurements have shown that many of these doubles are true binary systems, the two components revolving round their common center of gravity in periods that range from 10 to 12 years, to unknown thousands and obeying, so far as these motions can show, the same law of gravitation that regulates the motion of the solar system. Sir William Herschel was the great pioneer in the field of discovery of these objects, but his measures were of comparatively little accuracy, and the elder Struve may be considered as the first astronomer to lay the foundation of this branch research. The field of first discovery of these double stars has thus far been principally covered by five astronomers, and most of the known doubles are usually called by the catalogue number of the works or discovery lists of these five men, with a distinguishing letter for each, although it is very generally the custom to call the star by the catalogue number of the elder Struve if it is contained in the "Mensuræ Micrometrice." These five astronomers, with their distinguishing letters, are as follows: Herschel, Sir William. H. Struve, F. G. W... Σ. Herschel, Sir John. h. O Σ. Struve, Otto. Burnham, S. W... .β..