BAIRD &TATLOCK (LONDON) LTD. 



1838 1839 



1838" Weights, brass troy cup form, in sets. 



o.i to 5 oz. 10 or.. 20 oz. 50 oz. troy. 



7/- 9/- 14/- 32/- per set. 



1839 U Oertling's Assay Weights, 10 grains and its subdivisions in 1,000 parts, in platina, for 

 assaying of silver 



1840" Oertling's Assay Weights, i gramme and its subdivisions in 1,000 parts, in platina, 

 for assaying of silver, as Fig. 1839 



250 



2 15 



1841 



1841" Oertling's Assay Weights, J gramme and its subdivisions in 1,000 parts for assaying of 



gold .. .. .. .. .. !. .. .. .. 1 10 



1842 



1842 U Oertling's Assay Ton Weights, fitted in mahogany block with lid, 4 to 0.05 A.T. per set 1 15 



A B C D 



Either: i AT=2g.i66 grammes ; i AT=32.666 grammes ; i AT= 291 f grains ; i AT ="326! grains. 



1843" Becker's Assay Ton Weights, of 4 " A.T." down to ^V " A.T." .. .. .. 14 



The Assay Ton Weights have been introduced by Prof. Dr. C. K. Chandler, of the School of Mines, Columbia 

 College, New York, where they are now in use for convenience in the assay of ores. The weight denominated 

 by Dr. Chandler I " A.T." equals 29.1666 grammes, and contains consequently as many milligrammes as there 

 are troy ounces in a ton avoirdupois of 2,000 Ibs. Therefore if i " A.T." of ore assays i milligramme, the ton 

 contains I ounce troy. 



CRO^S STRET HATTCTK GARDEN, E- C 



