862

THE COLLIERY GUARDIAN.

April 23, 1915.

CURRENT SCIENCE

Coalfields of India.

In the Memoirs of the Geological Survey of India
(vol. xli, Parts I., II.) the coalfields of India are dealt
with. In Part I., Mr. R. R. Simpson brings up.to date
the late ,Prof. V. Balls’ general survey of the whole of
the coalfields of the Peninsula; while in Part II.,
Dr. L. L. Fermor describes in detail the geology and
hitherto undeveloped coal resources of Korea State,
Central Provinces. Air. Simpson States that, in addi-
tion to the Gondwana coal fields of permo-triassic age*
there is upper Jurassic coal in Kutch and the Trans-
Indus Salt range; while cretaceous coal fields occur in
the Khasia and Garo hills in Assam, and tertiary coal
fields are found in the foothills of extra-peninsula
India, from Baluchistan t> Assam, and also in Sind,
Rajputana, Burma, and the Andaman and Nicobar
islands. The Dainuda coal fields, in the Gondwana
system, are alone of the first importance. The coal
is laminated bituminous, with alternating dull and
bright layers. Much of it does nob cake freely, although
certain seams yield fairly good coke. The ash content
varies from.1 Oto 25 per cent. There is no true anthra-
cite, the nearest approach being the crushed and
powdered coal at the foot of the Darjiling Himalayas.
Aloisture is variable, being II per cent, in the Godavari
and Wardha areas, while in the Raniganj field it varies
from 1 per cent, in the Barakar stage to nearly 4 per
cent, in the upper seams of the Raniganj stage.
Phosphorus and sulphur are variable, but there is
plenty of coal suitable for iron and steel manufacture.
The whole extent of the coal-bearing strata covers
35,000 square miles. Much detailed information is
given of the seams worked in different districts.

Dr., Fermor shows that coal of good quality and in
seams of workable thickness occur in both the Sanhat
and Kurasia coal fields, which are of Gondwana age.
The seams usually have a sandstone roof, but water is
likely to be abundant. Conditions are believed to be
favourable for the development of coal mining in this
part of the Central Provinces, but transport facilities
must first be provided. A railway in this area is
wanted, quite apart from the prospects of coal mining,
as a valuable export of grain, lac and timber would
thus be assisted. The Geological Survey of India
maintains its characteristic activity in the investigation
of promising sources of mineral wealth throughout the
country.

Briquettes of Washery Sludge and Coke Breeze.

Experiments have at various dates been made with
the object of obtaining a satisfactory fuel by briquetting
washery refuse and coke breeze, residuals that ordinarily
command but little value. In Germany coke briquettes,
in which sulphite pitch was used as a binder, have been
tried in blast furnaces and on torpedo boats with pro-
mising results, the advantage of sulphite pitch over coal
tar pitch for this purpose being that it does not soften
under heat and burns at a high temperature. Tests
carried out by the United States Bureau of Mines, how-
ever, seem to indicate that this binder is affec ed by
moisture in the material to be briquetted. Some ten
years ago, it may be added, the Semeb Solvay Company
erected a plant at Detroit to utilise its accumulations of
coke breeze.

The practicability of utilising small cual and coke in
this way has recently engaged the attention of some of
the.foremost manufacturers of briquette machinery in
this country. About three years ago, we believe, Me-srs.
Wm. Johnson and Sons, of Armley, Leeds, went into
the matter very fully, erecting a plant at their works
for the purpose of carrying out tests. These established
the fact that a good fuel could be obtained, although
the ash contents vTere rather high. The shape of
briquette adopted was the “ eggette,” weighing from ll
up to 7 or 8 oz.; from 4 to 5 oz. being a convenient
size for general purposes. Messrs. Baldwins subse-
quently ordered from Messrs. Wm. Johnson and Sons
a briquetting press, equipped with a vertical heater or
cooker, in order to carry out more extensive tests at their
Bandore works. Experiments with one of the “patent’
binders were not satisfactory, and this aggltitinant was
discarded for pitch; several hundreds of tons of fuel were
produced, which was used extensively during the coal
strike in 1912. Experience, however, showed that owing
to the high percentage of ash it was desirable to wash
the coke breeze before use in the press, but some diffi-
culty has- been experienced in obtaining a suitable
washer for the purpose, the first plant installed having
proved a failure. Owing to the shape of the briquettes
and the large amount of air space between the fuel, the
heat produced in burning was very great, so that the
ash contents were reduced to clinker, and the boiler
men complained that the fires required to be cleaned
out at frequent intervals, although they acknowledged
the high heating properties of the briquettes. No
detailed particulars of the tests are available, but it
may be mentioned that the final experiment at Landore
was made on a locomotive used for taking slag ladles
from the furnaces to the tipping ground. It was noted
that in using ordinary steam fuel the locomotive always
lost a lot of steam going up the incline, the pressure
falling from 150 lb. to about 80 lb. per sq. inch.
Using the “coke-coal” eggettes the Journey was
accomplished with a loss of only 20 lb. of pressure.

One point remains to be carefully considered—z.e.,
the relative proportions of washery, slurry and coke
breeze. Owing to the large percentage of water in the
slurry it is not possible to use a large proportion of this
material unless it has been previously dried. Conse-
quently it is advisable to include in the plant a small
dryer, similar to those employed on plants using
powdered fuel for steam Taising. This tends to raise
the' initial cost of the plant, but adds greatly to its
efficiency.

Another well-known firm in Leeds—Messrs. Yeadon,

AND TECHNOLOGY.

Son and Co.—have also carried out experiments with
highly-satisfactory results, we are informed. With
pitch at a low price, the opportunity of utilising such
products is one that must appeal strongly to manu-
facturers anxious to reduce their fuel bills to the lowest
limit.

Valuation of Lenticular Coal Beds.

In Economic Geology, vol. ix., No. 8, Messrs. G. R.
Rogers and C. E. Lesher discuss the use of thickness
contours in the valuation of lenticular coal beds. The
coal beds of the tertiary and cretaceous formations of
the Western United States usually occupy small basins,
and are liable to rai id variations in thickness. Thickness
contours, or isopachous lines, are imaginary lines con-
necting points of equal thickness. Thus these lines
give a method of showing graphically the thickness
variations over a given area. Such lines can only be
drawn from detailed field data. The method cannot be
satisfactorily applied to any but flat-lying strata, or at
any rate where the dip is small. The method of dt awing
these lines is precisely similar to that for drawing
ordinary contours. The accuracy of the lines will
depend upon the completeness of the field data, but
doubtful positions can easily be distinguished by broken
lines The authors give examples of the construction of
these lines in typical cases. In the first example, the
coal bed is shown to be a symmetrical lenticle of well-
defined extent. It is easy in such cases not only to
locate favourable sites for development, but also to
calculate the total available tonnage of the whole
deposit. In another selected example an elongated
outcrop of coal, extending for 18 miles, is examined by.
this method. The bed varies greatly in thickness from
place to place, and the thickness contours show clearly
the different lenses of which rhe deposit consists. The
structure of these lenses dispels at once a possible
illusion gained in the field as to the extension of this
coal bed. The economic value of thickness contours
differs in each case ; it is only in case of marked and
regular variations in thickness that their full value is
seen. They have, however, a distinct scientific value
with regard to the conditions of deposition of the coal.
There is probably some relation between the thickness
contours of the coal bed and the topographic contours
of the old surface upon wh’di it was formed, but the
value of this relationship depends upon whether the
datum plane is the top or the bottom ot the bed, and in
most cases this is difficult, if not impossible, to ascertain.
Thus in a coal bed, if plant growth was more rapid in
one place than another, if local erosion or channelling of
the bed took place after deposition, or if the bed was
not formed under normal conditions, the thickness
contours would fail to be any measure of the old
topography. In any case, tinckness contours add greatly
to an exact knowledge of a coal bed, and possess the
advantage of summing-up graphically a large mass of
detailed data, thus avoiding much verbal description,

THE GERMAN AND AUSTRIAN COAL
AND IRON TRADES.

We give below further extracts from German
periodicals that have reached us, showing the course of
the coal and iron trades in Germany and Austria:—

German Ironfounders’ Association.

The Association has issued a circular letter stating
that, in consequence of the continued increase in prime
costs, all the affiiliated district groups I ave decided to
advance the price of all castings by at least 10 percent,
equivalent to 2 mk. per 100 kilos., for the current
quarter.

Increases in Iron Prices.

The ironfounders in Eastern Germany have decided
to advance the price of castings by a further 2 mk. per
lot) kilos., equivalent to a rise of 10 per cent. The
Heavy Plate Union announces that the price of ordinary
plate will be, raised to 140 mk., constructional plate to
145 mk., and boiler plate to 155 mk. (advances of
12'50-15 mk.), whilst export prices are put up by 15-20
percent. The wire drawers are making the following
advances in price :—Bare commercial wire, 16 mk.; rod
wire, 15'75 mk.; screw and rivet wire, 18 75 mk.;
galvanized wire, 20 mk.; galvanized barbed wire, 25 mk.;
and wire nails, 17 mk. Rolled wire is raised another
15 mk. per ton, and bars another 10 mk. per ton.

Iron Market in Upper Silesia.

In contrast to the increased activity in Central
Germany, the iron market in Upper Silesia has remained
extremely quiet, and the prohibition of exports rendered
relations with neutral countries even more unsatis-
factory. The demands of the trade and private con-
sume) s remained small, and the slight, improvement
recorded has been chiefly due to the increased prices,
Buyers wishing to cover their requirements before
further advances are notified. Shipments via Vienna
and the Danube have been quite suspended, and those
vid Cos LOderhafen are insignificant. Nevertheless,
most works have nothing to complain of in respect of
bus ness, some departments being very well occupied on
war material at remunerative vri es. The difficulty
arising from scarcity of labour and certain raw materials,
restriction or stoppage of output in some works, and
heavy increase in the cost of production, still continues,
and is even accentuated, so that selling prices have gone
up once more. In rolled iron a number of large inland
contracts have been booked at good prices, for delivery
not later than the end of June; but orders for
building material are very scarce. Large orders are in
hand for railway superstructural material, but there is
little doing in girders and similar products, though a,
revival is expected before long for the railway work-

shops and wagon builders, as well as for neutrals. On
the other hand, heavy plate has been in good demand,
chiefly in high-grade material for shipbuilding, and
tube makei s have been taking large quantities of tube
plate. Makers of fine plate are extremely busy, and
cannot promise delivery under several weeks. Prices
are again higher. Extensive foreign orders in hand are
having to be delayed. Business in tubes has been
moderate, but makers have found themselves compelled
to raise prices by reducing the discount on gas pipe by
I per cent, and boiler tubes 2 per cent. The scrap iron
trade is better, and the recent fear of scarcity has
vanished, there being plenty of material available,
especially from railway shops, so that many works have
been able to lay in stocks and thus provide against
such contingencies as congestion of railway traffic.
Prices for ordinary scrap rule 56'60 mk., core scrap
50 mk., turnings 49 mk., repair shop turnings 51 mk.,
and melting iron 43'75 mk. per ton, delivered free.

EXPLOSIVES IN COAL MINES.

The Home Secretary has made an Order dated
March 30 under Section 61 of the Coal Mines Act,
191 J, substituting amended. provisions for those pre-
viously in force under Clause 1 (e) of the Explosives in
Coal Mines Order of September 1, 1913, in regard
to the custody and use of detonators.

The nev Order has been rendered necessary by the
Judgment of the High Court of Justiciary in Scotland
on October 22, 1914, in the case of Tennant v.
Allardice, which decided that under the existing Order
detonat >rs might, in mines other than those to which
Part II. of the Order applies, be issued to ordinary
miners, and not to the officials of the mine (in the
ordinary acceptation of the term) only, as was intended
by the Order.•

It will also be observed that the new provisions
expressly require that detonators shall be kept, until
issued, in a place of storage provided under Clause 1 (a)
of the principal Order, and that each such place of
storage shall be under the sole control of the manager
or some one person specially authorised by him to have
sucn control for the time being. This will not preclude
different persons being put in charge of different places
or of the same place during different shifts. All that
is required is that each place shall during any particular
period be under the sole control of a single individual
(whether the mana . er himself or some person authorised
by the manager).

The text of the Order is as follows :—

1.	The Explosives in Coal Mines Order of the 1st September,
1913, shall be amended, and shall take effect as if for
paragraph (e) of Clause 1 of the said Order the following
provisions were substituted :—

(i)	Detonators shall be kept in a place of storage
provided in pursuance of Clause 1 (a) of this Order until
issued.

(ii)	The detonators in any place of storage as aforesaid
shall be under the sole control of the manager or some
one person specially authorised in writing by the manager
to have such control in respect of that place of storage
for the time being.

(iii)	The manager or other person for the time being
having control of detonators as aforesaid shall only issue
detonators—

(а)	in mines to which Part II. of this Order applies, to

shotfirers appointed in pursuance of Clause 6 of
this Order ;

(б)	in other mines, to such officials of the mine, who shall

be either firemen, examiners or deputies of the
mine, or underground officials of the mine superior
to the firemen, examiners or deputies, as are
specially authorised in writing by the manager
for the purpose. Provided that, in any such
mine, if shotfirers are appointed for the mine
subject to the same conditions and having the
same duties as shotfirers in mines to which
Part II. of this Order applies, detonators may be
issued to such shotfirers.

(iv)	Every person to whom detonators are issued as
aforesaid shall keep the detonators until they are about
to be used for the charging of a shothole, in a suitable
case or box, which shall be provided by the owner and
which shall be kept securely locked and separate from
any other case or box containing explosive, and shall be
used only for the storage of the detonators.

(v)	No person shall take into the mine or have in his
possession in the mine any detonators except in accordance
with the foregoing provisions.

(vi)	In the case of a shaft being sunk from the surface
or deepened, it shall not be deemed a contravention of
the foregoing provisions if the primers for charges are
fitted with detonators on the surface before being taken
into the shaft, provided the primers are so fitted in a
workshop established under section 47 of the Explosives
Act, 1875, and are only taken into the shaft immediately
before use by the shotfirer or other authorised person and
in a thick felt bag or other receptacle sufficient to protect
them from shock.

2.	This Order may be cited as the Explosives in Coal
Mines Order of the 30th March, 1915.

A New Permitted Explosive.

An Order has also been issued, dated April 1, 1915,
adding the following explosive to the explosives named and
defined in the First Schedule:—

Cambr'de No. 2, consisting of the following mixture:—
Parts by weight.

f *

Ingredients.	Not more Not less

than	than

Nitro-glycerine ............... 21	...	22

Nitrate of barium .............. 4'5	...	3

Nitrate of potassium .....-.... 29	...	26

Wood-meal (driedat 10 degs. C.) 35	...	33

Carbonate of calcium .........   1	...	—

Chloride of potassium ........... 9	...	7

Alois ture.................... 6	...	3'5

The explosive is to be used only when contained in a non-
waterproofed wrapper of parchment paper ; with a detonator