Mr. J. Napier 07i Copper Smeltmg. 353' 



The average wear of bottoms made with this quality of sand 

 was lour weeks to five weeks, when they melted away or became 



Cwm Ivy, Wales : — 



Silica 89-8 



Peroxide of iron . . 4-4 



Lime 2-8 



Magnesia . . . . 1-6 



Carbonaceous matters -9 



99^ 

 The average wear of bottoms of this sand was two weeks. 

 Pembre, Wales : — 



No. 1. (Mr. Cameron.) No. 2. (Mr. Field.) 



Silica . . 93 

 Oxide of iron \ 

 and aluminaj 

 Lime . . 3 



loo 



Silica . 92-20 

 Carb.oflirae 3-46 

 Magnesia 0-06 

 Alumina 1-56 

 Oxide of iron 1-84 



100-12 



Average wear of bottoms made of these sands was six weeks. 

 But the name of locality is no guarantee as to quality/ as the 



lollowmir two annlvspa nrill cln^^ ^ *'-' 



following two analyses will show 

 Pembre : — 



Silica . . . . 

 Oxide of iron . . 

 Lime .... 

 Magnesia and soda 



100-00 100-00 



Bottoms made with these did not stand longer than two weeks, 



and proved liable to break up in a few days. 



Bow Common, London, found a little under the surface and 



washed before using :— 



Silica 96-5 



Oxide of iron ... 3-3 

 Lime and magnesia . -2 



Too-o 



The average wear of bottoms made of this sand was between two 

 and hree months .showing how analysis and practice agree, and 

 sUica '"' ^''' '"''"^'' ""'^^ '^""^ containing most 



An aluminous or clay sand, although sufficiently refractory as 

 Phtl. Mag. S. 4. Vol. 4. No. 20. Nov. 1852. 2 A 



