50 
NATURE 
[May 15, 1902 
most interesting note is now appended, in which the 
“Stokes theory of fluorescence,” to which references 
have been made from time to time by Lord Kelvin and 
others, is expounded for the first time in the author’s 
own words. Apart from the special application, the 
dynamical problem here employed by way of illustration 
is remarkable as the first example of the peculiarities of 
wave-propagation in a medium of “ periodic” structure, 
a question which has been further elucidated by Lord 
Rayleigh. 
The dates attached to the papers in this volume are 
all included in the interval from 1850 to 1852. The 
marvellous productiveness of the author, and the massive 
quality of the work which has left so little opening for 
subsequent correction or criticism, alike command our 
admiration. At the same time, we realise how great 
were the powers which from that period onwards were 
claimed in an increasing degree by the duties of the 
Lucasian professorship and by the secretaryship of the 
Royal Society. The generous and sympathetic manner 
in which these powers were placed at the service of 
younger workers now become a tradition of English 
science. 
At the end of the preface we read, “ There are other 
papers which still remain, and I hope, should life and 
health last, to put these together without delay.” The 
‘other papers” here so modestly referred to include such 
things as the “Communication of Vibrations” and the 
“ Report on Physical Optics”! That the life and health 
may long continue, and that the promised continuation 
may speedily appear, will be the earnest desire of 
every reader of this volume. HORACE LAMB. 
ANTHRACITE MINING IN PENNSYLVANIA. 
The Anthracite Coal Industry. By Peter Roberts, 
Ph.D. Pp. xii +261. (New York: the Macmillan 
Company ; London: Macmillan and Co., Ltd., 1901.) 
Price 15s. net. 
T is not often that a great industry is discussed in so 
thorough and useful a manner as has been done by 
Dr. Roberts in this case. He has brought together 
information from a large number of sources, and he 
presents pictures from many points of view; his twelve 
chapters relate to geology, methods of mining, capitalisa- 
tion, transport, management and inspection, workmen 
and wages, incidental profits, accidents, strikes, unionism, 
reworking old waste heaps and general reflections. 
The days of the “mammoth vein,” often exceeding 
100 feet in thickness, are coming to an end, and we learn 
that much of the anthracite is obtained from seams only 
two to four feet thick. It is estimated that, allowing a 
yearly output of sixty million tons, the stock of anthracite 
will last for eighty years. 
The actual cost of production is reckoned to be $1°25 
a ton, to which must be added royalties, insurance, 
office expenses and taxes amounting to about thirty- 
one cents, so that the total cost is about $1°56. 
Much has been said in this country about the danger 
of employing a few Poles in our collieries, on account of 
their imperfect knowledge of English. What should we 
think of a mining population talking twenty different 
NO. 1698, VOL. 66] 
languages, as happens in parts of the anthracite region? 
The majority of the alien colliers hail from Russia and 
Austro-Hungary. The author’s ethnology is at fault, 
however, when he says that the Bohemians do not 
belong to the Sclav nations. 
The chapter upon the incidental profits made by 
mining companies from running stores is by no means 
the least interesting ; it seems that the truck system still 
flourishes in Pennsylvania, in spite of legislation against 
it, and that the workmen have a real grievance. 
The accidents follow the usual lines; as in other 
districts, the proportion of fatalities due to falls of coal 
and rock approaches one-half of the total. The truth of 
the assertion that most of the accidents are due to care- 
lessness on the part of the men themselves may be 
doubted, though the apologists of the owners and 
managers of mines on this side of the water are too 
ready to endorse this statement. Recent statistics show 
that, at all events in Germany, it is incorrect. 
The author takes an unnecessarily pessimistic view 
concerning mining fatalities when he remarks that legis- 
lation is impotent to prevent them ; the experience of 
European countries is totally opposed to this conclusion. 
However, a cursory glance at the statistics for Pennsyl- 
vania might lead an outsider to agree with Dr. Roberts, 
for he shows that after years of law-making the annual 
mortality-rate from accidents exceeds 3 per 1000. Un- 
fortunately, he fails to make it clear whether this is the 
death-rate of the underground workers alone or that of 
all the persons employed both below and above ground. 
But in either case it is very high and very discreditable, 
and, what is worse, there are practically no signs of im- 
provement during the last quarter of a century. 
One cannot help suspecting that an inefficient method 
of enforcing the law may be at the root of the evil. 
Instead of being appointed for life, the inspectors hold 
office for five years only, and at a salary which in 
America may fail to secure thoroughly trustworthy and 
independent persons. It is not surprising, therefore, to 
find the suggestion that the inspectors are in the hands 
of the mine-owners. By a law which has come into force 
recently, the number of inspectors is to be increased, and 
they are to be elected by popular vote and for three 
years only. It will be interesting to watch how far this 
change will remedy the dangers of anthracite mining. 
Even if the next decade does show an improvement, it 
will not be necessary to ascribe it to the new inspectorial 
system. The author points out that a very powerful 
syndicate has lately acquired the control of four-fifths of 
the entire anthracite industry, and that with better 
administration, better discipline, improved methods of 
mining and increased use of machinery, the present dire 
waste of human life is likely to be diminished without any 
further legislative pressure. 
While dealing specially with the anthracite industry, 
the author discusses various social and economic 
problems, and his book deserves the attention of mining 
men generally, whether employers or employed. It isa 
matter for regret that we have not similar works relating 
to each of our own coalfields, or at all events a general 
treatise dealing in a like manner with coal-mining in the 
British Isles. 
