20 REPORT—1890. 
chrome-steel produced in the Loire district now receive important and 
continually-extending applications, because they combine comparative 
hardness and high tenacity with but little loss in ductility, and acquire 
great closeness of structure when tempered. 
The influence of chromium upon the character of steel differs in 
several marked respects from that exercised by manganese; thus, 
chrome-steels weld badly, or not at all, whereas manganese-steels weld 
very readily, and work under the hammer better than ordinary carbon- 
steel. Again, the remarkable influence of manganese upon the magnetic 
properties of steel and iron is not shared by chromium. Chrome-steel has 
for some time been a fermidable rival of the very highest qualities of 
carbon-steel produced for cutting-tools, and of the valuable tungsten- 
steel which we owe to Robert Mushet. The great hardness, high 
tenacity, and exceeding closeness of structure possessed by suitably- 
tempered steel containing not more than from 1 to 1:5 per cent. of 
chromium, and from 0:8 to 1 per cent. of carbon, renders this material 
invaluable for war purposes: cast projectiles, when suitably tempered, 
have penetrated compound steel- and-iron plates over 9 inches in thickness, 
such as are used upon armoured ships of war, without even sus- 
taining any important change of form. The proper tempering of these 
projectiles necessitates their being produced hollow; their cavities or 
chambers are only of small capacity, but the charge of violent explosive 
which they can contain, and which can be set into action without the 
intervention of fuse or detonating appliance, suffices to tear these formi- 
dable punching-tools into fragments as they force their way irresistibly 
through the armoured side of a ship, and to violently project those frag- 
ments in all directions, with fearfully destructive effects. The employ- 
ment of chromium as a constituent of steel plates used for the protection 
of ships of war is already being entered upon, and the influence exerted by 
the presence of that metal in small quantities in steel employed in the 
construction of guns is also at present a subject of investigation. At 
Crewe, Mr. F. Webb has for some time past used chromium, with con- 
siderable advantage, in the production of high-quality steels for railway 
requirements. 
The practical results attained by the introduction of copper and of 
nickel as components of steel have also recently attracted much attention. 
At the celebrated French Steel Works of M. Schneider, at Creuzot, the 
addition of a small percentage of copper to steel used for armour-plates 
and projectiles is practised, with the object of imparting hardness to 
the metal without prejudice to its toughness. James Riley has found 
that the presence of aluminium in very small quantities facilitates the 
union of steel with a small proportion of copper, and that the latter ins 
creases the strength but does not improve the working qualities of steel. 
With nickel, Riley has obtained products analogous in many important 
respects to manganese steel; the remarkable differences in the physical 
