On two occasions, therefore, the silver plate of this country was of finer quality than the coin of the realm: on the first when the coin of the realm was debased, and on the second when silver plate was compulsorily raised to a higher standard than the coin of the realm. The lion _passant_, which is the standard mark, has naturally been employed by provincial offices as a guarantee of sterling or standard silver. During the period 1697 to 1720 the lion _passant_ disappears from all silver in the “Britannia” standard period when other marks were substituted. But in 1720 the lion _passant_ mark occurs again on all London silver, and in Chester, Exeter, York, and Newcastle marks. From 1773 both Sheffield and Birmingham have used the mark of the lion _passant_. In regard to Scotland, the standard mark for Edinburgh, after 1757, is a thistle, and for Glasgow a lion _rampant_ after 1819. The Irish standard mark is a harp crowned from the year 1638, which mark is on all Irish silver assayed at the Dublin office. From 1730 the figure of Hibernia has been the duty mark and the harp crowned the standard mark on all Irish silver assayed at Dublin. These marks are shown in Appendix (pp. 347-409). III. THE DATE MARK Among the various marks used for the purposes we have indicated, the date mark is one which has a vital significance. It establishes with certainty the year in which a piece of silver was fashioned and taken to the assay office to be stamped as sterling silver. The easiest plan in regard to date marks would have been to stamp the actual date upon each piece of silver or gold assayed, but this was too simple a procedure for the “Mistery of the Goldsmiths.” They employed alphabets of various styles and each year was represented by a different letter, and to add further to the puzzling difficulty of deciphering these symbols, certain letters were omitted. Moreover, each assay town has its own series of date marks. Letters of the alphabet are used sometimes from A to T, or A to U, or from A to Z; sometimes the letters J and V are omitted, and in one case for a considerable period the letters of the alphabet were used indiscriminately. Various kinds of type were used and they appear in shields of differing shapes. The study therefore of the date marks of the London assay office and of the various provincial assay offices together with the date marks used in Scotland and in Ireland is very intricate, and the determination of these with exactitude might occupy a man the greater portion of his life. The standard work on the subject is “English Goldsmiths and their Marks,” by Mr. C. J. Jackson, which contains over eleven thousand marks reproduced in facsimile. Mr. Jackson in the 1905 edition had worked for seventeen years at this subject, and his labours have been stupendous; a new edition shortly to appear will represent a quarter of a century’s work. There is no other book on the subject within measurable distance of this encyclopaedia.