August 13, 1915.

THE COLLIERY GUARDIAN

319

be at a locus within the Lanarkshire area long before
any local brigade could be gathered together.

Messrs. James Black (Shettleston) and Riddell
(Bothkennar) considered -that the Lanarkshire coal
owners were to be commended for introducing the newer
system in respect that the establishment of these central
rescue stations took the responsibility of superintending
local teams and equipment away from colliery managers,
who, as the outcome of recent legislation, were already
overburdened with work.

Mr. John McLuckie (Larkhall) said he quite approved
of the newer system, for the simple reason that he
thought the rescuers under it would be much more
competently and efficiently trained. These men were
at these stations faced with a daily round of duty—■
handling and practising with the apparatus under a
variety of conditions—whereas the men attached to local
colliery teams were not in the same position at all.
Men who were only accustomed to wearing the
apparatus occasionally could never be expected to do
the work as well. In cases of disaster there would
always be a certain amount of nervousness about them
—a kind of haunting fear that possibly something would
go wrong with the apparatus with which they, due to
their limited knowledge, were unable to cope. It had
been urged that men attached to a local team would,
in cases of difficulty, prove more useful than men from
the central station who had not the same knowledge
of roads, etc. He could not endorse that contention,
because, he did not see if miners had to go to a rescue
station in order to be trained in the use of the apparatus,
how, on the other hand, members of a central brigade
ought not to go to the collieries at intervals and thus
familiarise themselves with the roads and the workings.
In collieries where there' was the least danger of
spontaneous combustion it seemed to him that such a
system of periodical visitation by the central brigades
could be arranged, and he felt, seeing the Lanarkshire
coal owners had gone so far in the right direction, they
would not leave that importantidetail out of account.

Lining Shafts with Reinforced Concrete Z Blocks.

An interesting paper was submitted by Mr. Marcel
Gillieaux, on “ Lining Shafts with Reinforced Concrete
Z Blocks.” A description of this process has already
appeared in the Colliery Guardian.*

The discussion on the paper was adjourned till next
meeting.

Immingham Coal Exports.—Returns for the week ending
August 6 show that the coal exported from Immingham con-
sisted of the following :—Foreign : To Dieppe, 963 tons; and
Havre, 1,051 tons—total, 2,014 tons foreign; against 59,072
tons foreign, and 465 tons coastwise during the correspond-
ing week last year.

Hull Coal Imports.—»The quantity of coal brought into Hull
during July (according to the return of the Hull Corporation
coal inspector) amounted to 467,917 tons—447,541 tons by
rail and 20,376 tons by river—as compared with 762,013 tons
in the corresponding month last year. The aggregate imports
during the period January to July reached 2,843,863 tons,
as against 3,885,596 tons in 1914. Coastwise shipments in
July were 55,347 tons, and the total for the first seven months
of the year 402,660 tons. Exports from the port during July
(exclusive of coal shipped for the use of the Admiralty and the
Allies’ Governments) were 283,733 tons, as against 454,736
tons; the quantity during the seven months ending with July
being 1,391,498 tons, as against 2,056,430 in the correspond-
ing period last year.

The Coal Trade of Holland. — A special correspondent
at Amsterdam of The Times says that a lively controversy
has arisen in Dutch coal trading circles in connection with
the Coal Bureau established by the Netherlands Government
for the regulating of prices and the equitable distribution of
coal supplies. This Coal Bureau is a branch of the Dutch
National Aid Committee formed at the beginning of the war
to relieve distress and prevent economic disturbance. It is
charged with the duty of receiving particulars of all the coal
in Holland. About two-thirds of this coal conies from Ger-
many, the remainder being derived partly from England and
partly from the Dutch minesi in South Limburg. The Coal
Bureau is presided over by Prof, de Vooys, chairman of the
executive committee of the National Aid Committee, and has
its offices in Utrecht. The trouble has arisen from the fact
that these offices are in the building of the Coal Trade Asso-
ciation at Utrecht. ■ This association is the selling agent of
the Rhenish Westphalian Coal Syndicate, a purely German
concern. Until now it has been optional for coal merchants
in Holland to associate themselves with the Coal Bureau, but
henceforth it is to be compulsory. The reason for this is that
the coal available for Holland is limited in amount by the
restrictions imposed both in England and Germany, and that
if it does not all go through the Coal Bureau that office runs
the risk, through the competition of the merchants not
affiliated to it, of being rendered useless for the purposes for
which it was set up. The Netherlands Oversea Trust has
therefore decided that all coal must be consigned to it, and
announced that it will not lend its assistance to any dealer
not affiliated with the Coal Bureau. A certain number of
dealers in English coal have protested very strongly against
this decision, on the ground that in disclosing all the details
of their trade to the Coal Bureau they are giving to the Coal
Trade Association (agent for a German syndicate) the very
particulars which will enable it to compete favourably with
them in future, and that, on the other hand, they are not,
en revanche, afforded the opportunity of inspecting the books
of the Coal Trade Association. They predict a complete cap-
ture of the Dutch coal market by Germany after the war as
a consequence of the step now taken. The weakness of their
position lies in the fact that a number of large buyers of
English coal have already joined the Coal Bureau, thus
affording an argument against the contention advanced.

* See Colliery Guardian, March 19, 1915.

THE MICROSCOPICAL EXAMINATION
OF COAL*

By James Lomax.

(Concluded from page 233.)

It will be seen by figs. 2 to 4 in the first description
of the Rugeley seam in the issue of January 8 (page 76),
and figs. 19 to 42, in the issue of July 30, pages 231 and
232, that the spore contents are very clbsely alike in
each seam, although in the Walsall seam there is more
variety in species to be found than in the Rugeley
seam. In both seams there occurs in the lower portion
the beautiful little megaspores as seen in fig. 2, page 76,
and figs. 19 to 22, page 231. These are consistent
throughout two-thirds the thickness of the seam,
gradually increasing in numbers as the thickness
increases, until ultimately the coal is almost composed
of them, as seen in fig. 31 vertical, fig. 32 horizontal.
There are other species of megaspores to be met with,
but not in a regular sequence or laminae like the former*
Some of these are to be seen in figs. 3 and 4, page 76,
figs. 25, 26, 30, 38, pages 231-232. They are more or
less isolated masses as might have occurred through the
shedding of the spores of a fruit cone in one particular
spot in the vegetable debris, or, as found by a whole
cone having been detached from its parent branch and
deposited in the vegetable humus beneath. The sizes .
and ornamentation of the spores show that they are of
different species. For instance, fig. 25 is of a large size,
having a thin wall or exosporium, tuberculated, whilst
others, such as fig. 26, have a spinosous covering of the
exosporium, and fig. 38, a large megaspore with libbon-
like appendages to the exosporium. Regarding the
microspores to be found in both seams, there is little
difference. In both seams they are to be found early
on, in regular laminae, forming a ground mass in which
are embedded other bodies. When first seen in the
■seams they are .very small, and appear to be all of one
species. Ascending higher in i^he seam they increase
in size, this will be seen by comparing fig. 2, page 76,
fig. 24, page 231, made from horizontal sections cut
about one foot from the base of the seam, with those
shown in figs. 3 and 4 vertical, page 76 (Rugeley).
Figs. 19 and 36 horizontal (Walsall) are taken from
sections cut about 3 ft. from the base of the seam.
The microspores are seen to be very much larger in the
latter than in the former. This is to be accounted for
Gy the different genera or species of lycopods they have
derived from. On reference to fig. 29, page 232, there
will be found a transverse section of a small cone
showing about eight microsporangia full of spores. The
microspores can be plainly seen in the sporangia, and
to be of a small size. It is obvious that they are from
two different genera of lycopods, the transverse section
being from a heterosporous cone cut through the upper
part or microsporangia, whilst the ground mass is com-
posed of the shed microspores of an isosporous cone, the •
former probably belonging to the Bothrodendrce, and the
latter to the Lepidodendrce. It is almost probable that
many of the large megaspores have been derived from
the Sigillaria, although it is not absolutely certain
except a complete cone could be found, but in fig. 37
vertical, there is to be seen in the centre a portion of
a microsporangia surrounde^ with megaspores; both
may have been borne on the same cone. Tissues of the
central axis or medulla of Sigillaria are also to be found
in both seams, showing that Sigillaria did exist and
flourish alongside the Bothrodendrce and Lepidodendrce.
It is evident to the writer, on the study of the sections
made from the two seams in regard to the lycopodaceous
remains, that in the lower portion commenced a growth
of more or less dwarfed and small lycopodaceous plants,
Lepidodendroid, or of the club-moss type, into which
came the Bothrodendrae and Sigillaria of the Selaginella
type, the Bothrodendrace and Lepidodendrce forming
the largest percentage of vegetable humus, in fact the
Bothrodendron becoming the dominant -genus of
lycopods during the deposition of vegetable matter now
forming at least 4 ft. thickness of the seam. After
which the Sigillaria gradually assumed the dominant
position, strangling, as one might say, the growth of
the others. If one examines the sections cut from the
region (hards or spore coal) this becomes evident. The
■spore coal in both seams is about the same thickness,
10 in. to 1 ft. 2 in., the lower portion being, as seen in
figs. 31 and 32, composed of small megaspores, being
gradually replaced by larger megaspores, as seen in
vertical and horizontal sections 33 and 34. Vertical and
horizontal sections 19 to 22 are similar to the
megaspores found in the lower part of the spore coal.
Horizontal sections 27, 28, 29, and 30 are from the
middle region of the spore coal,’and 35, 36, 37, and 38
are from the upper part of the spore coal. The figures
show the relative size of the megaspores as the
magnification is alike, being about 12 diameters. One
of the most striking features is the sudden stoppage of
the deposition of the lycopodaceous spore remains in
the vegetable debris, and the consequent return of the
fine humic matter to that found in the base of the
seams. The size and quantity of both microspores and
megaspores decrease quickly until within the space of
a few inches in vertical height above the spore or hards
the coal substance contains comparatively few spores.
The last four figs., 39 to 42, show the relative size and
ornamentation of the megaspores immediately above
the spore or hard coal. It will be noticed that the
size of the spores in fig. 42 corresponds to those found
in fig. 27, taken from the lower part of the hards.
Lycopodaceous fructiferous remains are very few above
6 ft. 2 in. from the base in either seam, but there is an
increase of the resinous and leaf bands found in the
middle and lower parts of the seams. There is also an
increase of fragmentary remains of stems, branches,
and cortex, in many places the tissues being exceedingly
well preserved. Figs. 11 and 12 horizontal and vertical

* A lecture read before the South Staffordshire and War-
wickshire Institute of Mining Engineers.

sections of two such stem remains. Fig. 10 is a portion
of a transverse section of a stem of Cordaites, and
fig. 12 longitudinal section of a similar stem.

It has already been shown that the g^mnospermic
order of plants have been fairly well represented in the
Shallow seam, both in the Rugeley and Wallsail districts,
It may be remarked here that the gymnosperms, during-
carboniferous times, played a far more important part
in the deposition of the vegetable debris than has
hitherto been accredited, some seams having been'
quite as dependent on their remains as others have been
on the lycopodaceous remains. Much of the soft, bright
laminated coal, owes its origin to the droppings of the
gymnosperms, also most of the resinous bands have
' been derived from the resin ducts and glands of the
same order. There are many genera besides the
Cordaites which flourished during the carboniferous
times, all more or less allied to those of recent times,
one genus Medullosa anglica stems of which have been
found having a diameter of nearly 12 in., with a large
spreading foliage fern-like in appearance (Alethopteris),
with seeds similar to those of a recent cycad. Many of
the seeds when complete were the size of a walnut, the
cast or kernel of similar seeds have been known for a
long time as Trigonocarpus. Remains of such seeds are
to be found in the coal sub dance of the Shallow seam.
Another genus belonging to the same order is the
Lepidodendrce, a plant less in size than the Medullosa,
but also having a fern-like foliage (Sphenopteris). This
genus, too, had seeds of a cycadian character
(Lagenostonia). Many of these have also been seen in
the ■Shallow seam, also stems, tissues and tracheides
as well as leaflets, showing that they, too, added their
duota to the vegetable debris now forming the coal
substance. Fig. 9, page 115, shows> large resinous
bodies magnified about three times, many being the
remains of seeds. Fig. 8 shows a laminae of resinous
bodies, some being also the remains of seeds. Fig. 6,
page 76, shows resinous bodies in the Rugeley seam.
Of leaf tissues we have two or three fine examples in
fig. 2, page 76, Rugeley, and figs. 6 and 7, page 115,
Walsall. It has already been mentioned that the
breaking up into dice or small coal may have influence
in originating spontaneous combustion. The Shallow
seam in both the upper and lower region are liable to
this, chiefly on account of its constituents undergoing
change when the weight or stress is released, either
laterally or vertically. From what the writer has seen
it is quite apparent that when there occurs a stratum
of brights lying between two bands of spore or spire
coal, there is an alteration caused by the expansion of
the more elastic or resinous bands, which is either the
spire or spore. This will be easily seen in fig. 5, page
76, referred to on the same page. In the upper part
of the figure is a spore coal, whilst the lower is the
bright; the latter’will be seen full of cracks breaking
up the coal dice-like. The upper portion being elastic,
has expanded, tearing the brights ip. so doing; heating
similar pieces artificially shows this to be the case.
Fig. 7 is a vertical section. Fig. 8 horizontal of a
similar piece of brights.

Regarding the inital cause of heating, it is difficult to
tell, except one could have experiments conducted under-
the same conditions as are found in the mine. But
there is this, as the writer has been trying -to show in
the present description, where coal is made up from
various substances, those substances acting primarily
(chemically or otherwise) for or against each other,
.changes then would occur, leaving as it were matter
partially inert, which on being exposed to or in contact
with conditions and substances suitable, would, as it
were, renew their activity. There are many suspicious
bodies to be found in the seams, the chief is the small,
shot-like bodies shown in fig. 9, page 76, referred to on
the same page. Similar coal which has been under
observation shows it to be very soon oxidised, forming
a yellowish-white salt-like substance, more or less in
appearance and taste like alum sulphate, the rest falling
into inpalpable dust. The little bodies are not true
pyrites, although there may be some amount of pyritic
matter in their composition. They are black, and not
unlike the globulites in appearance, although the
globulites are much larger and better defined. Further
evidence on the above subject is needed before one can
state definitely what is the initial cause. The writer
has already pointed out the importance of microscopical
research in regard to coal. He feels, too, that justice
cannot be done to such research in a communication
similar-to the present, for as one examines the sections
-more minutely, many other things become apparent,
which have to be left out. This being so, what would
one be able to find if—instead of making an examina-
tion of the vertical thickness of a seam, which means
neither more or less than a thin slice, no more than
1,000th part of an inch thick, with the corresponding
horizontal sections, both combined not covering an area
of more than a few square inches throughout the thick-
ness of the seam—an examination were made, say, of
the 30 ft. seam, covering an area of several square feet
or yards? He believes that the future has in store far
greater results than has ever in this direction been
thought of, which can be put to practical uses both
scientifically and commercially.

In conclusion, he would like to thank the president of
the South Staffordshire and Warwickshire Institute of
Mining Engineers for the trouble in obtaining the
samples of the Rugeley, and also Mr. Peake for the
Walsall samples. The sections will be ultimately
housed at the Birmingham University and the Natural
History Museum, South Kensington. From each of
the seams there has been made a series of photo-
micrographs coloured to the same tint as in the sections
themselves; these will go with the sections—the
Rugeley sections, with a series of coloured photographs
of the Walsall seam, to the University Birmingham;
the Walsall sections most likely to South Kensington;
so that they will be available to any who are desirous
of studying them.