458 
merely of aluminium, the basis of many light 
alloys, but also of magnesium, which is now 
being manufactured on a considerable scale 
in Great Britain. The production of electro- 
lytic zine, an increase in the output of copper 
alloys, the introduction of metals in the pow- 
dered form, a considerable extension of die- 
easting methods, and a general marked im- 
provement {in technical practise are other 
directions in which this little exhibition gives 
ground for satisfaction in the character of 
our industrial awakening. 
AIRCRAFT AND ROAD MOTORS 
One section of the exhibition shows what 
has been done by the alliance of science and 
industry to secure that supremacy in the air 
which is essential to success in modern war- 
fare. The principles which govern design, 
materials of construction, trend of develop- 
ment in aircraft engines, the use of para- 
chutes to enable airmen to make a safe de- 
scent from a damaged machine, the utiliza- 
tion of women workers in aircraft factories— 
all these things are either illustrated or sug- 
gested. 
Another group of exhibits illustrates what 
has been done by the Gas Traction Committee 
to promote the employment of gas in substi- 
tution for petroleum products as a source of 
power for motor vehicles, and a completely 
fitted road transport vehicle shows the high 
pressure equipment which has been approved 
by the committee for the purpose of an ex- 
periment on a commercial scale with 20 
motor-omnibuses in London service. 
ELECTRICAL APPARATUS 
In the electrical section the display is a 
little disappointing, but the progress in this 
and other departments of manufacture which 
have called for the assistance of research 
workers is indicated, where the exhibits fail 
to show it, by the excellent series of special 
articles which form the first section of the 
official catalogue. Two outstanding develop- 
ments are, however, the subject of exhibits 
in the electrical group. One of them shows 
what has been done to establish a British 
SCIENCE 
[N. S. Von. XLVIII. No. 1245 
magneto industry, with the result that during 
the past four years 300,000 magnetos have 
been manufactured for war service alone. 
The measure of this achievement is expanded 
by the claim which car be justly made that 
the British magneto is as good as that for 
which German manufacturer previously held 
a monopoly. The other exhibit illustrates the 
progress of electric welding. 
The display of scientific instruments is also 
somewhat meagre, but it has been difficult 
for maunfacturers to withhold deliveries 
which were in urgent demand, and the ex- 
hibition has been robbed to serve the needs 
of the country. Much progress has, how- 
ever, been made in original design, and the 
output during the war to meet the require- 
ments of the Admiralty, the Ministry of Mu- 
nitions, and the Air Board has been remark- 
able. The exhibits sent by the National 
Physical Laboratory indicate some of the lines 
of advance, a particular example being the 
mirror extensometer, a type which was form- 
erly made in Germany. The exhibit from the 
Teddington establishments shows the char- 
acter of the experimental work which is now 
being carried on in the gauge rectifying shop 
with the object of speeding up the manu- 
facturing process and of obtaining an in- 
creased degree of accuracy. 
CHEMICAL INDUSTRY 
If the special work which has been under- 
taken on behalf of the engineering trades has _ 
been selected for attention here, it is not be- 
cause equally good results have not been ob- 
tained in other industries, but because the 
situation in engineering was essentially typ- 
ical of that which existed at the outbreak of 
war. Nothing which has been accomplished 
during the past four years is of greater im- 
portance than the work in connection with 
chemical products and processes. The graye 
deficiencies in the supply of the materials for 
the production of explosives, dyes and drugs, 
and the lack of trained chemists to supervise 
manufacturing processes, have been largely 
overcome, while experimental work in con- 
nection with the supply of intermediate prod- 
