108 ANNUAL OF SCIENTIFIC DISCOVERY. 



The action of the laminating is more striking, because, under 

 the hammer, the metal is so soon cooled ; that is, it has to be re- 

 heated from time to time, "which operation complicates the work ; 

 in using a laminating machine the work is done with extreme 

 rapidity, especially if care is taken to heat the alloy to a red heat. 

 At an ordinary temperature a single passage under the lamina- 

 tors would break the sheet in thousands of pieces. This alloy can 

 be cut at a high temperature like iron and steel, and presents the 

 fine and homogeneous grain of the latter; it is soldered without 

 difficulty with^he ordinary jewellers' solder. 



The following tests will demonstrate that the density of the 

 bronze suffers very little modification by the hammering or lami- 

 nating process : 



Chinese Bronze. Density nftcr Smelting. Density after Hammering. 



Bronze at 21.5 per cent, tin, 8.938 8.929 



Bronze at 18.5 per cent, tin, 8.882 8.938 



Bronze at 20.0 per cent, tin, 8.924 } 



Bronzo at 20.0 per cent, tin, 8.918 > 8.920 



Bronze at 20.0 per cent, tin, 8.912 ) 



ZINC AS A BUILDING MATERIAL. 



Stone, and stone only, says the " American Builder," has 

 always been deemed, by architects and others, the appropriate 

 material to be employed in the ornamentation of buildings, and 

 doubtless there has existed, until a comparatively recent date, the 

 best of reasons for this theory. First, stone is durable ; there is 

 nothing ordinarily entering into the composition of our buildings 

 that, in this respect, can compare with it ; and again, from its 

 peculiar facilities, few other suitable substances can be worked 

 into the required form, offering the means for such boldness and 

 strength in the general effect, or such correctness and delicacy of 

 detail. On the other hand, however, stone can be employed only 

 at a considerable expense, both in working and transportation, 

 and, in some localities, distant from quarries, this expense reaches 

 a point where the employment of such material is practically pre- 

 cluded, save where its use is an absolute necessity. In orna- 

 mented fronts especially, where stone has heretofore been con- 

 sidered indispensable, its use is being discarded, and metal 

 imitations are taking its place. 



The principal objections raised against the use of metal lie in 

 the fact that it is untruthful, and, therefore, inappropriate ; but 

 certainly the use of an imitation in this particular is in no sense 

 more appropriate than the use of hollow iron columns in imita- 

 tion of stone, and the employment of similar counterfeits in in- 

 terior ornamentation. Prominent" among the substitutes for stone 

 is zinc, a material which has proved eminently adapted to the 

 purpose, and is rapidly acquiring a place among the building 

 material from its adaptability to all forms as well as from its last- 

 ing qualities. With the introduction of pressed ornaments of 

 tliis material the expense of exterior decorations has been greatly 



