1818.] On English and Foreign Copper, Zinc, and Brass. 125 



Article XII. 



On English and Foreign Copper, Zinc, and Brass. By T. Gill, Esq. 



(To the Editors of the Annals of Philosophy.) 



No. 11, Covent Garden Chambers, 

 GENTLEMEN, July 14, 1818. 



In Dr. Tliomson's History of Physical Science, published in 

 your Annals for last month, page 20, speaking of brass, he says, 

 " A friend of mine in London, who excels in the construction of 

 time-pieces, showed me a piece of brass which he valued very 

 highly. He gave it the name of old Dutch brass, and informed 

 me that he was in the habit of buying it up whenever he could 

 find it, and paying much higher prices than were demanded for 

 modern brass. He was one of those persons who have a much 

 greater veneration for former ages than for that in which they 

 happen to live." He then proceeds to state, that " the old 

 Dutch brass was much more ductile than Biistol brass with which 

 I compared it." This is surely a much better reason for his 

 friend's preference than his " veneration for former ages ; " and 

 he is by no means singular in his opinion, and indeed is well 

 justified in his practice by the vastly superior purity, ductility, 

 and malleability of the old Dutch, or, more properly, Nurenberg 

 brass, which to watch-makers is invaluable, and has long been 

 employed by them. 



The late Mr. Harrison made his celebrated time-pieces of old 

 Dutch pan brass ; and Mr. Hardy was recently furnished with 

 some of it by the Board of Longitude, in whose hands it had 

 been preserved from the time of Mr. Harrison, to make a time- 

 piece with for the Royal Observatory at Greenwich. 



When it is considered that the foundation of the very superior 

 accuracy and delicacy of finish of time-pieces and watches, rests 

 entirely upon the excellent quality of the steel, and the purity and 

 malleability of the brass, which they are composed of, it is by 

 no means singular that watch-makers should prefer that brass, 

 which so far excels every other in these important respects. 



The Dutch or Nuremberg brass owes its superior properties to 

 processes, which are veiy different to those followed in the 

 manufacture of brass in this country ; and, indeed, until copper 

 is brought to that degree of purity and malleability as to be 

 capable of being beaten into leaves by the gold beater's process, 

 similar to Dutch leaf metal ; and that zinc shall be entirely, freed 

 from the lead, tin, &c. with which it may happen to be combined 

 in the ores by other processes than those usually employed in 

 this country, namely, of mixing the ores of zinc with copper to 

 make brass, or of distilling them, per descensum to extract the zinc, 

 which also carries down with it lead, tin, &c. it will be in vain 

 to hope to make brass equal to the old Dutch brass, and as 

 capable of being beaten or rolled into thin tinsel, or drawn into 



