; APRIL 30, 1914] 
. 
a 
NATURE 
phy: 
Canada cannot be compared with the mineral 
statistics of other countries unless these causes of 
inflation are taken into account, it is obvious that 
the Canadian mining industry is flourishing, and 
forms an important item in the wealth-producing 
power of the Dominion. 
Important as was the mineral production in 
IQII, it appears to have been quite eclipsed by 
that of 1912, for it may be taken for granted 
that the figures contained in the General Sum- 
mary, just issued, are not likely to be greatly 
modified in the final report. This gives the grand 
total of the entire mineral output, made up as 
it was in IQII, as 135,048,296 dollars, equal to 
an increase of 308 per cent. There is no new 
feature of any importance, except perhaps that 
the gold production shows an increase of. about 
40 per cent., due to the Porcupine district of 
Ontario. The silver output has fallen off slightly 
in Cobalt, but all other metals show an increased 
production. By far the most important mineral 
product is still coal, and as its output has in- 
creased by 28 per cent., this alone would cause 
the year to compare favourably with its predeces- 
sor. All that can fairly be said is that the 1912 
report shows clearly that the mineral produc- 
tion of Canada is steadily growing in import- 
ance. 
It is to be regretted that the scheme of Cana- 
dian mineral statistics takes no account of the 
labour conditions of the industry, and that no 
information is given concerning the number of 
men engaged in the industry, the wages earned 
by them, and of the accidents, fatal or non-fatal, 
that have befallen them during the year. Statis- 
tics on these points ought to be forthcoming in 
order to enable students of the subject to form a 
clearer picture of the course of development of the 
mineral industry of the Dominion. 
The Report upon the production of the various 
metals in Canada may be taken as a final report, 
whilst it at the same time goes into somewhat 
greater detail than is possible in the General Sum- 
mary, and also devotes more especial attention 
to the economic side of the subject. It can only 
be said fully to confirm the impression given by 
the General Summary as to the flourishing con- 
dition of the Canadian mineral industry. 
The Summary Report of the work performed 
by the Mines Branch of the Department of Mines 
forms most interesting reading, and indicates that 
the Mines Branch is carrying out a vast amount 
of research work for the benefit of the mineral 
industry of the Dominion. A report upon the 
metallurgy of cobalt and its alloys, and another 
upon recent progress in the electrical manufacture 
of iron and steel may be named as indicating the 
nature of the work being carried on; it is most 
satisfactory to find evidence of the existence of a 
Government Department equipped for conducting 
such researches upon modern scientific lines, and 
to have such proof that the Canadian Government 
is far-seeing enough to give such excellent assist- 
ance to an important industry. It may fairly be 
said that if Canadian mineral industries are 
NO. 2322, VOL. 93] 
flourishing, the result is due not only to the great 
resources of the Dominion, but to the enlightened 
policy of a Government which devotes its energies 
to turning these resources to the best possible 
account. 
IMPROVEMENTS IN THE BINOCULAR 
MICROSCOPE. 
ICROSCOPISTS long ago appreciated the 
advantages that might accrue could both 
eyes be employed to view the object by means of 
a “binocular ” microscope—the natural method of 
viewing objects with both eyes would be preserved 
and eye-strain lessened, and stereoscopic vision 
may be attained. 
The viewing of an object with both eyes not 
only lessens eye-strain, but there is a summation 
of stimuli in binocular vision, and, even without 
a stereoscopic effect, a better appreciation of the 
object viewed is probably obtained—there is 
greater “‘vividity”’ about the image. 
Three principles have now been applied in the 
construction of the binocular microscope. The 
first of these is the use of two complete micro- 
scopes pointed obliquely at the same object, as in 
| the Greenough binocular. This form has but a 
limited application as it is adapted for low-power 
work only. In the second form, best represented 
by the “Wenham” binocular and its modifica- 
tions, the light coming from a single objective 
FIG. 3. 
Fic. 2. 
is “geometrically” divided, 7.e., the beam is bi- 
sected and half is directed into each eye. This 
is accomplished by interposing one or more prisms 
in the path of the beam as shown in Fig. 1. 
This type of instrument involves the use of long 
tubes and is consequently bulky, resolution is 
diminished by reducing the size of the beam of 
light, and it cannot be used with high powers as 
the dividing prism cannot be placed sufficiently 
close to the back lens of the objective properly 
to bisect the beam before the rays have inter- 
mingled. 
The third form alone embodies correct prin- 
ciples. In this, of which the Powell and Lealand 
and Abbé are the best examples, the beam of light 
is not bisected, but is physically sifted or filtered, 
so that a portion of every part of it goes to each 
eye. This “sifting” or “filtering” is accom- 
plished in the forms mentioned by interposing in 
