Ee 
SEPTEMBER II, 1913| 
and the systematic study of corrosion in condenser 
tubes of various composition under conditions as 
nearly like those of practical service as possible in an 
experimental condenser plant set up by the committee 
at Liverpool University. The results as stated in the 
report are remarkable, and diverge widely from the 
views generally accepted hitherto. The examination 
of material from service did not lead to any conclu- 
sive results, but the data furnished by the experi- 
mental plant—so far as they yet go—confirm the 
results of the small laboratory experiments. The 
report deals entirely with the process of corrosion by 
dezincification, which the authors have found to be 
the most common form of corrosion, although it 
appeared in the discussion that they admitted that 
pitting does occur in the absence of dezincification. 
They find, however, that none of the alloys tested by 
them undergo selective corrosion or dezincification 
when exposed to sea-water at the ordinary tempera- 
ture, but they are all subject to it at higher tempera- 
tures, the process becoming vigorous towards 40° C. 
The action of dezincification is connected by the 
authors with the formation of a basic zinc chloride, 
or of zinc hydroxide, which is found attached to the 
surface of the tube, and under these patches the metal 
is dezincified. The action of this basic salt is described 
as regenerative and dependent upon the presence of 
dissolved oxygen in the water. The experiments of 
the authors dealt with four alloys, viz. brass, contain- 
ing copper 7o per cent., zine 30 per cent.; Muntz 
metal, containing copper 61 per cent., zinc 39 per 
cent.; ‘‘Admiralty’’ brass, containing copper 70 per 
cent., zinc 29 per cent., and tin 1 per cent.; and a 
special alloy, containing copper 7o per cent., zinc 28 
per cent., and lead 2 per cent. As regards resistance 
to dezincification at 4o° and 50° C. the last-named 
proved superior to the others, the Muntz metal and 
70/30 brass being the least resistant. Another in- 
teresting and surprising result obtained by the authors 
is that dezincification does not appear to be due to 
electrolytic action; they find—contrary to what has 
been generally believed—that the presence of particles 
of carbon, or similar materials, even including a plug 
of pure copper screwed into the tube, does not give 
rise to local action of this kind. The report contains 
a detailed account of the experiments upon which 
these conclusions are based, and thus constitutes a 
record of work which must be of fundamental import- 
ance in the future study of the whole question of 
corrosion in copper alloys. 
Of considerable general interest also 
paper on the intercrystalline cohesion of metals 
by Dr. W. Rosenhain, F.R.S., and Mr. D. 
Ewen, of the National Physical Laboratory. The 
authors of this paper elaborate their theory that the 
crystals of a metal, forming a crystalline aggregate, 
are held together by a thin layer of the same metal 
in the amorphous or undercooled liquid condition. The 
experimental evidence offered in their first paper they 
now supplement by evidence obtained from an entirely 
different direction. In the present paper the relative 
mechanical properties of the crystals and of the 
amorphous cement are discussed, and the authors 
indicate that while at ordinary temperatures the 
cement would be much harder and stronger than the 
crystals, at temperatures near the melting point this 
relation must be reversed, since the undercooled liquid 
cement must pass into the ordinary fluid condition in 
a gradual and continuous manner while the crystals 
will soften suddenly on melting. Just below the melt- 
ing point, therefore, the theory indicates that the 
crystals could be pulled apart from one another with- 
out undergoing any distortion, thus giving a perfectly 
brittle fracture—the brittleness being entirely jinter- 
crystalline. The authors show such brittle inter- 
NO. 2289, VOL. 92] 
was the 
NATURE 
53 
crystalline fractures in the case of the purest lead, tin, 
aluminium, and bismuth, the lead fractures being par- 
ticularly striking in appearance. At the meeting these 
data were supplemented by a similar brittle fracture 
obtained in a bar of the purest gold which had been 
prepared for the authors by Dr. T. K. Rose, of the 
Royal Mint. The discussion showed that the theory 
of an amorphous cement is still ‘received with some 
reserve, but it was admitted that the accumulation of 
experimental evidence has considerably strengthened 
the position of the theory. 
The list of papers dealt with at the meeting in- 
cluded nine others, among which those of Dr. T. K. 
Rose on the annealing of gold, of Dr. W. M. Guertler 
on the specific volume and constitution of alloys, of 
Prof. S..L. Hoyt on the constitution of the copper- 
rich kalchoids, or alloys of copper, zinc, and tin, of 
Mr. J. H. Chamberlain on volume changes in alloys, 
and of H. Garland on the metallographic study of 
some Egyptian antiquities, were of considerable in- 
terest. The discussions were in all cases vigorous and 
full of ‘interest, and the meeting marks a decided 
advance in the development of the Institute of Metals. 
THE PAST SUMMER. 
BRO4aDLY speaking, the past summer was essen- 
tially dry, generally cool, and particularly sun- 
less considering the small amount of rain. 
The reports issued by the Meteorological Office 
show that for the whole period of thirteen weeks 
which comprise the summer the mean temperature 
was below the average in all parts of the United 
Kingdom except in the north of Scotland, the 
deficiency being greatest over the east and south-east 
of England. The mean temperature was higher than 
in Ig12 over the entire kingdom with the exception 
of the east of England, but it was everywhere much 
cooler than in the abnormally hot summer of 1911, 
the difference being greatest in the midland, southern, 
and eastern districts of England. 
The sunshine was deficient over the eastern portion 
of the kingdom, but generally in excess in the western 
districts. The hours of bright sunshine were every- 
where more numerous than in 1912, but far fewer 
than in 1911. Taking the British Isles as a whole 
the total hours of sunshine were 492 in 1913, 373 in 
1912, and 679 in 1911. 
The average rainfall for the whole of the British 
Isles for the three summer months—June, July, and 
August—was 447 in. this year, 12-92 in. last year, 
and 627 in. in 1911; the average number of rainy 
days are thirty-five this summer, sixty-one last year, 
and thirty-seven in 1911. The rainfall this summer 
was less in all districts of the United Kingdom than 
in the dry summer of 1911. In the south-west of 
England the aggregate summer rainfall was only 
39 per cent. of the average, in the north-east of Eng- 
land 44 per cent., and in the midland counties and 
the south-east of England 45 per cent. The wettest 
districts were the north of Ireland, 68 per cent. of 
the normal, north-west of England, 67 per cent., and 
north of Scotland, 66 per cent. 
At Greenwich, which fairly represents England, the 
weather at the end of May was persistently hotter 
than at any time during the summer. On six con- 
secutive days the sheltered thermometer rose to 80° 
or above. Throughout the summer, from June to 
August, there were only four days with 80° or above, 
the average number of such warm days for the 
summer is fourteen, and in rg1r there were thirty- 
seven days as warm. 
The following are the chief meteorological results 
at Greenwich :— 
