1874.] Metallurgy. 121 
have been smelted for use in making the bronze weapons and implements 
known to have been used at an early epoch of civilisation. 
METALLURGY. 
Some valuable researches on alloys, especially on those of copper and tin, 
have been conducted at the Paris Mint by M. Alfred Riche, who has recently 
published his results in the “ Annales de Chimie et de Physique.’? The 
fusibility of the alloys was determined by means of Becquerel’s thermo- 
ele&tric pyrometer, with platinum and palladium wires, constructed by 
Ruhmkorff. The author finds that most alloys of copper and tin suffer 
liquation at the moment of solidification, and hence it is almost impossible to 
obtain their true melting-points. Exceptions, however, are furnished by those 
alloys whose atomic constitution corresponds to the formule SnCu; and 
SnCu,; these alloys are not liquated, and the former of them possesses 
peculiar properties, differing in colour, for example, from all others of this 
class. Tempering increases the density of bronzes rich in tin, and annealing 
diminishes the density of tempered bronze. Whilst steel is hardened by being 
suddenly cooled, bronze is softened by this treatment. Yet the bronze is not 
sufficiently soft to be readily worked; and it has long been a vexed question 
how the Chinese manage to work their tam-tams and other instruments of 
bronze. Experiments made many years ago at the Ecole des Arts et Métiers, 
at Chalons, showed that such objects might, though with much trouble, be 
wrought in cold-tempered bronze; but the process was too difficult to be 
employed industrially. It was afterwards asserted by St. Julien that the 
Chinese worked their bronze at a red heat; yet it was difficult to understand 
this, since bronze is extremely brittle at high temperatures. M. Riche appears 
to have settled the difficulty by showing that although bronze cannot be 
readily worked either cold or at a bright red heat, yet it is easily manipulated 
at intermediate temperatures. Taking advantage of this fact, M. Riche and 
M. Champion have succeeded in imitating the Chinese tam-tams. 
With respec to unalloyed copper, Riche finds that its density when alter- 
nately submitted to mechanical treatment, tempering and annealing, is 
variously affected according as the metal is protected from or exposed to access 
of air; in the former case the mechanical action increases, and in the latter 
case diminishes the density. The introduction of a small proportion of iron 
gives considerable tenacity and hardness to copper. The author has also 
studied a number of alloys of copper and zinc. 
Within the last year or two considerable attention has been dire@ed to the 
so-called ‘* Phosphor-Bronze,” an alloy of copper and tin, with more or less 
phosphorus, according to the purposes for which it is intended. Messrs. 
Montefiore-Levi and Kiinzel have brought this alloy to great perfection, and 
have applied it to a great variety of industrial uses, whilst in this country it 
has been prominently brought forward by the Phosphor-Bronze Company. 
When the proportion of phosphorus is large the alloy is extremely fluid, and 
therefore well adapted for castings; whilst its fine colour and close texture 
recommend it for decorative work. Certain forms of the bronze are charac- 
terised by great ductility and malleability; and may be readily rolled, drawn, 
or embossed; whilst other varieties are as hard as soft steel, and may be 
worked into tools and cutting instruments for use in gunpowder mills. It has 
been much recommended for ordnance and small arms; whilst the miner has 
used it for the wire ropes of his winding machinery, and the iron-smelter for 
the tuyeres of his blast-furnace. Numerous experiments on the mechanical 
properties of phosphor-bronze have been made at Berlin and Vienna, and by 
Mr. Kirkaldy in this country. 
A detailed account of some experiments on Swedish steel, conducted by 
Mr. Kirkaldy, at his Testing Works at Southwark, has lately been published. 
The specimens tested were manufactured at the Fagersta Works by Mr. 
Christian Aspelin, and have been exhibited at Vienna. The enquiry was 
directed to the behaviour of the steel under the action of tensile, compressive, 
