62 SECTIONAL ADDRESSES. 
the cementation of iron, heat treatment, and many others, including the 
first ‘ freezing-point ’ curve of a series of binary alloys in 1875. It was in 
consequence of these that his co-operation was invited by the Alloys 
Research Committee, whose first six reports contained a great deal of his 
work, covered a wide field, and did much towards the realisation by engineers 
of the value of microscopical and thermal methods in the study of metals. 
Later reports to this committee, whose work in 1902 was transferred to the 
National Physical Laboratory, have maintained their high standard, and 
have been contributed to by such workers as Carpenter, Hadfield, and 
Rosenhain. 
The last of these reports, the eleventh, embodies work at the National 
Physical Laboratory from 1914 to 1918, the year when that institution 
became a part of the Department of Scientific and Industrial Research. 
It deals with light alloys, the need for which the war has emphasised, 
especially in connection with aircraft. For this purpose the Laboratory’s 
work has resulted in furnishing alloys of aluminium with zinc and copper, 
with copper and manganese, and with copper, nickel and magnesium, 
possessing remarkable and useful properties, such as high tensile strength 
at ordinary and also at raised temperatures. 
Since the war light aluminium alloys continue to be studied at the 
National Physical Laboratory, which is the Government establishment 
where metallurgical research is carried out mainly for the advancement of 
knowledge. Here has been worked out the constitution of many important 
systems, binary, ternary, and quaternary, in which aluminium is the 
largest constituent, and the wire models constructed for the ternary alloys 
have proved of great value in the study of their constitution. Such ques- 
tions as age-hardening have been investigated and the cause ascertained. 
Systems with copper as the dominant metal have been investigated 
as regards their constitution, as well as the effect on their mechanical and 
electrical properties of known additions of other substances that may be 
present as impurities. 
But attention is also being given to ferrous alloys for whose investiga- 
tion specially pure components have to be prepared, in order to eliminate 
the effect of impurities of which a very small proportion may often have 
a marked influence on the product, and several equilibrium diagrams 
with iron as the main component have been worked out. Research on 
the more physical side includes investigations on the heat evolved during 
the plastic deformation of a metal, on the effect of heat treatment and 
composition on the magnetic properties of tungsten steels, on fatigue, and 
on the physical constants of metals. By the application of X-ray analysis 
to the crystal structure of metallic systems, Rosenhain has obtained 
confirmation of his conception of the nature of solid solutions. 
The chemical section of the National Physical Laboratory carries out a 
large amount of work in connection with these researches, the investigation 
of methods of analysis, and the preparation of standards for the analysis 
of steel, as well as chemical work of a non-metallurgical nature. 
Maintained by the Fighting Services since 1904 to increase the efficiency 
of the metals used in the manufacture of ordnance and armament, the 
Metallurgical Branch of the Research Department, Woolwich, increased 
in numbers, building and equipment during the war, and at present employs 
about 25 metallurgists. It has been occupied for the most part with steel, 
