8 Annals of the Carnegie Museum. 



either gold or silver, after the quality of the metal has been ascertained 

 by analysis at the Assay Halls of the Goldsmith's Company of London. 

 The privilege of assaying and marking precious metals was conferred 

 upon this honorable body by statute in 1300 A. D. and a charter was 

 granted in A. D. 1327. The powers of the company have been con- 

 firmed by subsequent acts of Parliament. The standard mark of the 

 London Hall is a lion passant for sterling silver and this was also the 

 mark on twenty-two-carat gold until the year 1845. The present 

 mark for gold is a crown and the figures, which indicate the purity of 

 the metal, such as " 18" for eighteen-carats. Prior to 1821 a crowned 

 leopard's head was also used as hall-mark. The exact year of 

 manufacture is indicated by a letter of the alphabet which is changed 

 each year on the last day of May. The standard of purity in gold in 

 the earlier watch-cases was much higher than at present, as it was not 

 until 1798 that a lower standard than twenty-two carats was allowed. 

 In that year the use of eighteen-carat gold was permitted. In 1854 

 three more standards were introduced, fifteen, twelve, and nine carats 

 of gold being admitted to use, 



Mr. H. J. Heinz, who has generously deposited this collection in the 

 Carnegie Museum, has used extreme care in the selection of the speci- 

 mens of which it is composed. A number of years ago he became 

 interested in the subject and began the formation of a collection. His 

 collection is much more extensive than that displayed, but he insists 

 that only the best specimens shall be exhibited. Quality is empha- 

 sized rather than quantity, though the collection is not by any means 

 small. So far as possible the catalog is arranged in chronological order 

 and the various steps in the- development of the watch from the por- 

 table dial to watches of modern times may be traced. The collection 

 has great educative value, not merely from the artistic standpoint, 

 but from the mechanical standpoint as well, since it is possible by its 

 help to study the evolution of watches as machines. For many reasons 

 the collection is worthy to be regarded as one of the most important 

 in the United States. 



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