758 
daylight are crimson, pink, or purple in gas or electric 
light. During the War, blue lamp bulbs were needed, 
but they had to appear blue when illuminated by the 
glow of a red filament. Had absorption spectra of 

colouring oxides been available, much money and | 
labour spent in fruitless experiments would have been 
saved. 
It was due to the measurements made by physicists 
on the indices of refraction of small crystals that the 
two crystalline forms of silica were detected, and the 
knowledge of the transformations has placed the 
whole manufacture of silica bricks on a sound 
scientific foundation. Recent work on X-ray spectra 
promises shortly to do for the fire-brick manufac- 
turer what a knowledge of indices of refraction has 
done for the silica-brick manufacture. 
Applications of magnetism have been but partially 
explored. One problem that has been almost solved 
is the separation of particles of metallic iron from 
clay slip. A system of electromagnets made by the 
Rapid Magnetting Company is ingeniously arranged 
so that if the magnets cease to work, the dirty slip 
will not pass into the purified slip. Success, however, 
has not yet been attained in removing particles of 
cupriferous pyrites from fire-clays. _ 
The physicist-engineer specialising in heat problems 
has an illimitable field for his knowledge and skill. 
Dr. Mellor estimates that in firing biscuit-ware only 
2 per cent. of the fuel is usefully employed, although 
the processes of brick-firing are much more efficient. 
Another series of problems awaiting solution is 
connected with the drying of clays and clay-ware, 
where serious losses occur owing to the development 
of drying cracks unless an inordinately long time is 
allowed. It appears that little progress is possible 
until the physicist has worked out the distribution of 
water in the interior of a drying mass of clay, and he 
will obviously have to take into account the relation 
between the surface of the drying solid and the 
humidity of the surrounding atmosphere. 
Dr. Mellor referred to the studies of the thermal 
strains in ‘‘ ideal’’ kilns upon which Prof. Lees is 
engaged ; later it is hoped to apply these results to 
actual kilns, and he expressed the wish that Prof. 
Lees would pass on to consider contraction strains 
set up during the uneven drying and firing of special 
shapes. The results of such an investigation will not 
only explain why some shapes fracture and others do 
not, but they will also indicate to the designer of 
chemical and sanitary apparatus, furnaces and coke 
ovens, the shapes to be avoided on account of the 
narrow margin of safety in manufacture and use. 
Numerous interesting problems relating to the grain 
of clay await solution. It appears, for example, that 
the particles can be oriented differently so that the 
drying and firing contractions are different in different 
directions. Then there is the plasticity of clays to 
be studied, and, indeed, the whole problem of the 
hydrostatics and dynamics of liquids with an \in- 
definitely large number of particles in suspension. 
Akin to this are the colloidal problems—now ever 
with us—but for some unaccountable reason, which 
he ascribed to chance, Dr. Mellor preferred to label 
this branch of his subject as chemistry and not physics. 
Electricity is usefully employed in high tempera- 
ture testing work, and also for crucible furnaces, 
but a satisfactory electric furnace for firing pottery 
has not yet been evolved, and in any case the cost 
of power is here a paramount consideration. Dr. 
Mellor indicated the novel problems connected with 
the effects of convection currents of hot air that 
would have to be solved if electrically-heated fur- 
naces or kilns came into use. The conditions are 
quite different from those in gas- or coal-fired furnaces, 
NO. 2796, VOL. 111] 
NATURE 


[JUNE 2, 1923 
In conclusion Dr. Mellor referred to the physical 
problems connected with the glazing of pottery. 
The governing condition here is that the thermal 
expansion of glaze and body should be the same. 
Data so far obtained have not taken sufficiently into 
consideration the complex adjustment of glaze and 
body ; for example, there is 
the glaze attacks the body and the effect of solution 
of the body in the glaze and its coefficient of expansion. 
The lecturer’s statement of the case for much 
closer co-operation between the ceramist and the 
physicist than has hitherto obtained was forcible and 
convincing. 
The Meteorology of Scott’s Last Journey. 
THE Halley lecture for 1923 was delivered at 
Oxford on May 17 by Dr. G. C. Simpson, the 
director of the Meteorological Office, who took for 
the subject of his lecture ‘“‘ The Meteorology of Scott’s 
Last March.” 
The polar party left Hut Point on November 3, 
rgit, and first traversed the Barrier, where it experi- 
enced a remarkable daily variation of temperature. 
In spite of the fact that the sun was continually 
above the horizon, varying only from 10° above the 
southern horizon at midnight to about 30° above the 
northern horizon at mid-day, the regular daily 
temperature variation on cloudless days reached 
the enormous value of 20°F. This necessitated 
travelling by night and resting by day. Several 
serious blizzards were encountered. 
It is now clear that the Barrier blizzard is extremely 
local, being confined to the western half of the Barrier. 
During ten months with simultaneous observation 
at Framheim—Amundsen’s winter quarters in the 
east—and at Cape Evans in the west, winds of more 
than thirty miles an hour occurred during 30 per 
cent. of the time at Cape Evans, and only 2 per cent. 
at Framheim. This is due to the fact that when the 
pressure is higher over the Barrier than over the 
Ross Sea the air tends to flow from the Barrier north- 
wards to the sea, but is deflected to the west by the 
earth’s rotation. The edge of the western plateau 
extends like a wall 8000 feet high for more than a 
thousand miles along the west of the Barrier and of 
the Ross Sea. This prevents the air moving freely 
to the west, with the consequence that the air-flow 
from the whole of the Barrier is concentrated in the 
west, and moves northward with high velocity, giving 
rise to the familiar blizzard. 
When the polar party was at the foot of the Beard- 
more Glacier it experienced a serious blizzard which 
gave the greatest snowfall ever recorded in high 
southern latitudes. The cause of this bad weather 
was the formation of a deep depression over the Ross 
Sea, which produced a great flow of warm air from 
the Ross Sea to the south of the Barrier. 
On reaching the plateau, low temperatures were 
experienced. During the five weeks that Scott and 
his party were on the plateau the mean temperature 
was -19° F., with a maximum of -3° F., and a 
minimum of -30° F. As they descended from the 
plateau, the temperature at first rose in the normal 
way, but while the party was still on the glacier a 
great change in the weather occurred. From thi 
date—February 11—until March 20, : 
abnormal conditions were experienced. There was 
little or no wind, the temperature fell rapidly to the - 
neighbourhood of -40° F., and ice crystals were 
deposited from the cold air upon the surface which 
acted like sand on the runners of the sledge. These 
thirty-nine days were the deciding factor in the fate 
= 
extremely — 
e tensile strength of — 
the glaze to be considered, as well as the rate at which - 













