Ocroser 9, 1913] 
y increasing the pressure at which the gas is supplied 
ery high temperatures under perfect control can be 
tained. Specimens of these different types of fur- 
es are also to be seen in other sections of the 
low the body temperature as to lead to chill; 
the capacity ‘for moisture of the heated air caused a 
degree of discomfort that led to prejudice being raised 
gainst this method of warming living-rooms. 
When, however, 
hygienic must always give a larger amount of radiant 
heat than of convected heat, advance was at once 
made, and the severe competition in which, in the 
last three years, the different makers of gas fires have 
dulged has resulted in the production of gas stoves 
hich give a high radiant efficiency. Further ad- 
vances are being made constantly, and it is anticipated 
that in a short time the percentage of radiant heat 
gi be more than double that which 
ammonia liquor are shown in the shops that serve to 
illustrate the best methods of show-window lighting. 
These are divided into three classes, tar, ammonia, 
and cyanogen products, the first class especially being 
worthy of attention. 4 
Another very suggestive exhibit is a series of com- 
partments illustrating the effect of the colour and 
surface of wall-papers on the amount of illumination 
btained from equal sources of light. Some valuable 
conferences have been arranged to take place during 
the period that the exhibition remains open, and 
especial interest will be felt in the promised discus- 
‘sion on the sanitary influence of gas lighting and 
heating, whilst the influence of gas as a fuel on smoke 
abatement will also receive its due share of attention. 
¥ 
CARNEGIE SCHOLARSHIP MEMOIRS. 
: a /Or- yv. of the Carnegie Scholarship Memoirs has 
e just been issued by the Iron and Steel Institute. 
_ The volume contains six papers which differ very’ 
widely in merit and interest, but on the whole it 
_ represents a considerable amount of important research 
work. It is unfortunate, however, that the practice 
of publishing these papers in a separate volume tends 
to relegate them to oblivion, and at all events robs 
- them of the advantages of discussion even by corre- 
spondence, thus lessening materially the value of the 
work done under the Carnegie scheme. 
__ The preservation of iron is dealt with by Dr. 
- Newton Friend; his results, if confirmed by future 
; sate experience, are of considerable importance. 
e 
paraffin wax to paint lessens very materially corrosion 
in iron and steel merely exposed to the air, but rather 
assists corrosion in the case of plates actually 
immersed in water. Increasing the number of coats 
NO. 2293, VOL. 92| 
NATURE 
finds that the addition of small quantities of | 
| creasing importance, and the older 
179 
of paint beyond two also appears not only to offer 
no increased protection, but actually to promote cor- 
rosion. This result leads one to-inquire whether the 
constant repainting of iron-work often practised on 
ships may not actually do more harm than good; at 
all events, an examination of some of these thickly 
painted surfaces should afford interesting evidence on 
the point. Finally, Dr. Friend finds that painting 
over a slightly rusted surface, from which, however, 
all lumps of scale, dirt, &c., have been removed, is 
actually more effective as against further rusting than 
the same paint applied to a completely cleaned surface 
—the only advantage of thoroughly cleaning the iron 
before painting lying in a better surface finish of the 
painted work. ; 
Another paper of special interest is that by Mr. 
J. A. Pickard dealing with the determination ~ of 
oxygen in steel. This is a question of steadily in- 
methods are known 
to be quite unsatisfactory. Mr. Pickard’s method 
consists in heating the drillings to be analysed in an 
atmosphere of hydrogen which is simultaneously kept 
in contact with phosphorus pentoxide, so that the 
concentration of water-vapour always remains very 
low. His results indicate a very satisfactory degree 
of accuracy, and the further application of his method 
| will be awaited with interest. 
A lengthy paper by Mr. A. Kessner deals with the 
!' development of the drill test for ascertaining the 
machining properties of steel; the author, working at 
Charlottenburg, has developed a form of apparatus 
whereby the rate of cutting under standard conditions 
can be measured with a considerable degree of accu- 
racy, and has used this to study the effect of several 
factors upon the machining properties of metals and 
to compare the ball-hardness and tensile properties 
of materials with their machining properties. That 
ball-hardness is not a guide to machining properties 
is a result which might have been anticipated, but 
whether the author’s form of drill test does not 
depend upon the measurement of a quantity which 
depends upon too large and complicated a system of 
factors yet remains to be proved. 
Of the more theoretical papers, that of Mr. Hum- 
frey, dealing with the influence of the intercrystalline 
cohesion of metals upon their mechanical properties 
is perhaps the most interesting. It is another step 
in the development of our conceptions of the internal 
mechanical constitution of metals, and although to 
some extent speculative, it is certainly suggestive, 
particularly as it offers the first attempt at explaining 
the mechanism of the effects of mechanical over- 
strain, which, while it raises the elastic limit in 
tension, and thus apparently hardens the metal, at 
the same time lowers the elastic limit in compression. 
Humfrey explains this by the development of severe 
internal stresses residing in the amorphous matter 
at the intercrystalline boundaries, these stresses tend- 
ing to resist further deformation in the direction of 
previous strain, but assisting stresses tending to pro- 
duce deformation in the opposite sense. 
The remaining papers, by Messrs. Hailstone and 
Swinden, are less satisfactory. The latter attacks the 
problem of the constitution of molybdenum steels by 
means of numerous cooling-curves and other data, 
but does not make use of the well-known methods 
of discussing and considering the equilibria of a 
ternary system. As a result of this lack of general 
theoretical guidance in the work, the data lead to no 
satisfactory’ conclusion. This want of systematic 
attack is typical of much of the work which has been 
done on steel, and especially on alloy steels, and 
probably accounts for the confusing differences of 
opinion which still exist in regard to their nature and 
constitution. 
