Dr. Pearson's Observations 
43 s 
more than one part of tin is added to three parts of copper to 
compose the most sonorous metal which is manufactured, 
namely, bell-metal.* But this aliay is too brittle to be beat 
out into a plate for making a trumpet ; and accordingly the 
lituus, which has been made of hammered metal, contains 
only about one part of tin and seven parts and a half of cop- 
per, § 7. p. 429. 
Copper is united with tin for the purpose merely of be- 
coming more fusible, and of continuing longer fluid, or cool- 
ing more slowly while passing from the melted, or fluid state, 
to the solid state. Such metal is used for making statues, and 
casts of figures in general, and is called statuary metal, -f and 
sometimes bronze. The proportions of the two metals are 
various ; probably according to the colour proposed, and the 
size and figure of the cast ; as well as on account of the price 
of the metals. 
A small proportion of zinc is sometimes added to allays of 
copper by tin ; on some occasions, on account of colour, on 
others, perhaps, to render the copper still less oxidable and more 
fusible ; and on other occasions, as 1 have found on inquiry, 
it is added from erroneous theory, or mere caprice. No one 
could tell me the use of zinc, which in some manufactories is 
added, in making gun metal. 
Tin might be used also to render copper less clingy, or 
* The proportion of tin varies in bell-metal from one-third to one-fifth of the weight 
of the copper ; according to the sound required, the size of the bell, and the impulse to 
be given. 
f The Greeks and Romans consumed vast quantities of copper in casts of figures. 
They added not only tin but lead to the copper. The proportions given by Pliny are 
one part of a mixture of equal quantities of lead and tin to fifteen parts of copper. The 
use of the lead I do not understand, if it was not to save expence. 
