378 NATURE 
[JUNE 13, 1912 
a circle around the zenith, and touches the halo 
only for solar altitudes of about 20°. 
The sun pillar, a column of light extending as 
much as 20° above the sun, is formed by reflec- 
tion at a horizontal face of a crystal, either simple 
reflection at a lower face or total internal reflection 
at an upper. 
The phenomena produced by refraction 
coloured; those due to reflection only 
white. 
Mr. Haskett Smith (Nature, May 30) appears 
to have observed the 46° and the 22° halos and 
the upper arc of contact of the 22° halo; the Rev. 
R. J. Roberts (The Times, June 1) appears to have 
seen the horizontal mock sun ring with the mock 
suns associated with the 22° halo. 
Dr. W. G. Smith sends a description of an 
observation at Armagh between 6 and 7 p.m. on 
May 26 of the halo of 22°, and apparently of the 
upper arc of contact of the 46° halo. Between 
noon and I p.m. on the same day, at Comlongon 
Castle, Dumfries, Mr. Whellens observed the 22° 
halo and a lateral tangent are of the 46° halo. 
Mr. David Smart observed at 6.45 p.m. on 
June 4, near Hove, three separate brightly- 
coloured patches, the sun being at the time hidden 
by cloud. The order of the colours and the 
approximate distances which he gives indicate 
that the patches were probably parts of the halo 
of 22°. 
Mr. Bartrum asks in Narure of June 6 if the 
needles would float vertically and the plates with 
their axes horizontal. Neither position would 
be stable. The needies would tend to _ set 
themselves horizontally and the plates with 
their axes vertical. The optical effects would, 
however, remain unaitered, the plates producing 
certain of the phenomena attributed to the needles 
and vice versa. Both Pernter and Mascart appear 
to have assumed that the crystals would take the 
direction for which the resistance to their motion 
was a minimum, and that the needles would be 
vertical and the plates with axes horizontal. 
E. G. 
are 
are 
CANADIAN MINERAL RESOURCES.} 
Re continued progress of the mineral industry 
in Canada is shown by the Annual Report 
and Statistics by Mr. John McLeish. Mineral 
statistics for the whole of the Dominion were first 
compiled in 1886, and the annual value of the 
production between then and 1909 has increased 
ninefold. The minerals raised in Canada in 1909 
were worth more than 6,300,000 dollars above 
those of the previous year. The most important 
increase was in the structural materials and clays, 
in which the rise was from _ 11,339,000 to 
1 Annual Report of the Division of Mineral Resources and Statistics on 
the Mineral Production of Canada during the Calendar Year 1909. By J. 
McLeish. Pp. 291. (Canada: Department of Mines, Ottawa, 1911.) _ 
Magnetic Concentration Experiments with Tron Ores of the Bristol 
Mines in Quebec; Iron Ores of the Bathurst Mines, New Brunswick s;A 
Copper Nickel Ore from Nairn, Ontario. By G. C. Mackenzie. 
figs. (Canada: Department of Mines, Ottawa, 1910.) Bulletin No. 5. | 
Report of Analyses of Ores, Non-metallic Minerzls, Fuels, &c., made in 
the Chemical Laboratories during the Years 1906, 1907, 1908. Pp. 126+2 
plates. By F. G. Wait. (Canada: Department of Mines, Ottawa, 1900.) 
Report on the Molybdenum Ores of Canada. By T. L. Walker. Pp. 
64+14 plates+1o figs. (Canada: Department of Mines, Ottawa, rgr1.) 
NO. 2224, VOL. 89| 
| 
ieteLese. 
16,533,000 dollars. The yield of the metallic 
products increased in value about 2,500,000 
dollars, but there was a fall in the total for the 
non-metallic minerals of a million dollars, 
The arrangement of mineral products into 
metallic and non-metallic is unsatisfactory owing 
to the ambiguity in the term “metal,” and the 
variations in its meaning introduce uncertainty 
into the comparison between the returns of dif- 
ferent countries. The Canadian report differs from 
general practice by including arsenic and chromite 
among the non-metals ; magnesite, pyrites, and the 
minerals of which aluminium and the alkalies 
are the chief constituents are regarded as non- 
metallic. 
The most striking development of the Canadian 
mineral industry during the year is the great in- 
crease of silver due to the mining field of Cobalt. 
It yields go per cent. of the total silver production 
of Canada, and about one-tenth of that of the 
world. The output both cf gold and copper has 
declined since 1908, and there has been a fall of 
nearly 400,000 short tons in the output of coal 
and of more than 100,000 barrels of petroleum. 
The rapid expansion of settlement in Canada has 
led to the great increase in the demands for build- 
ing materials, which have contributed the largest 
rise to the iineral products of the year. 
Canada is poor in iron ores of present com- 
mercial value, but has large supplies of low-grade 
ores, and is therefore especially interested in the 
problem of their oncentration. Mr. G. C. Mac- 
kenzie’s Bulletin -ecords the results of a series 
of experiments on magnetic concentration, a pro- 
cess which appears particularly suitable for iron 
ores. The many countries which have large 
deposits of banded ironstones will watch the 
progress of the Canadian investigations with in- 
Mr. Mackenzie has experimented with 
three ores. The first was a low-grade magnetite 
from the Bristol Mines in Quebec; the magnetite 
is mixed with ielspar, quartz, hornblende, and 
calcite, and is associated with much pyrites. This 
ore was found to be easily concentrated magnetic- 
ally, and 7o per cent. of the sulphur was eliminated. 
By the use of a wet method oo per cent. of sulphur 
was removed, and the phosphorus reduced to a 
trace. The concentrated ore, as in all these cases, 
would have to be briquetted before smelting. 
The second ore tested was a siliceous ironstone 
from the Bathurst Mine of New Brunswick, and 
represents a widespread type. The iron occurs in 
minute particles of magnetite and hematite. The 
results showed that a satisfactory magnetic con- 
centration by the dry process is impracticable; a 
wet method, however, gave a somewhat more 
encouraging result. 
The third series of experiments was on the 
separation of the copper and nickel in the ore 
from Nairn, Ontario. The experiments in this 
case were incomplete, and the separation unsatis- 
Pp ete | factory. 
Mr, F. G. Wait’s report consists of the analyses 
made in the years 1906-8 in the chemical labora- 
tories, and contains many interesting contributions 
to the geology and economic mineralogy of 
