September 18, 1914.

THE COLLIERY GUARDIAN.

629

this went to show that old customs were hard to break,
and the housing problem was not so simple as it looked
at first sight. Another consideration, which should not
be lost sight of, was that mining was a risky specula-
tion, and even in the most promising place closing down
might follow a few years after sinking. Coal owners,
therefore, had much justification for jerry-building. The
president had asked the writer for his conclusions, and
these were :—The speculative builder being out of the
question, good results would most likely be got by (1) a'
State service of housing, or (2) State aid and control
of private enterprise.

With regard to regularity of work, he (Mr. Gibson)
regretted that he had used words implying incredulity
of the figures advanced by Mr. Sneddon, and frankly
confessed that for the moment he had forgot that figures
from a comparatively small area might seemingly con-
tradict those from a large area of which it was a com-
ponent part. Mr. Bron had contended that the large
bulk of the miners worked steadily, which was quite
true. He was, however, on less solid ground when he
minimised the loss due to the irregularity of the
minority, as the following table would make clear :—

Day.	Lttendance.  Per cent.	Output.  Per cent.	Remarks.
Monday		.	95	..	.	90 ...	Last day of pay.
Tuesday		.	88	..	.	87 ...	First day of new pay.
Wednesday	..	90	..	.	90	
Thursday ..	.	94	..	.	94	
Friday 		.	99	..	.	99 ...	Pay day.
Saturday ..	.	75	..	.	60	
Average		.	90	..	.	86	

These percentages were based, not on perfect attend-
ance, but on reasonable attendance; that was to say,
men with a valid excuse for absence were not taken
into account. The output was 13’per cent, below what •
it ought to be, and if the cost per ton for management,
maintenance, handling of output, etc., was 2s. per ton,
it was 3d. too high. These figures were not empiiical
data, but were relatively correct, and therefore reliable.
The custom of the country seemed to tend in the direc-
tion of making Saturday more and more a holiday. If’
this were so, the fact must be accepted. But why
should the attendance be better on the last day of the
pay than the first? Colliery managers all over the
country found this held good. The sidelight this threw
on the miners’ outlook on life was most interesting,
and repaid close consideration.

Mr. Dron questioned the views held by the writer on
what was known as the “ family income ” and its
effect on -mining economy. Cases could be adduced of
collieries in remote districts where wage rates were very
high and costs low. It would be found that old men
were scarce in such districts, most of the workmen being
in the prime of physical strength—namely, from 25 to
40. Most men with daughters migrated at about 40.
Men were scarce and wages high because auxiliary indus-
tries did not exist. Costs were low because amongst
other things labour must be economically used, and
possibly because the men were in the prime of life.

With regard to the criticism on the cost of hard-
drawing, as the writer had in view the preparation of a
paper on that and kindred subjects, he did not at present
purpose going further into the subject.

Mr. Dron held that a premium system must in the
long run cause a permanent increase of cost, because the
conditions varied so much, and because the miner would
take concessions, but would not give them. He (Mr.
Gibson) was not quite sure whether the second argu-
ment was meant to be contingent on the first. If so,
he saw no logical connection. The reply to Mr. Dron
was :—(1) Miners were pretty much like other men,
and if premiums and rewards paid in other industries,
Mr. Dron must show that miners were not as other men,
or that mining was so different from any other industry
that the system was inapplicable in this particular
industry; but (2) in other industries premiums were
paid under the most diverse circumstances; (3) the
writer advanced economic argument to show that the
ultimate result of increased wage rates might be
reduced, not increased, costs, and Mr. Dron had not
questioned the reasoning. Finally, premiums had been
paid for many years back in mining in various countries,
notably in the sinking of the deep shafts in South
Africa.

The writer had stated that “ Real economy meant
economising labour,” and the president had questioned
the wisdom of that maxim. It did not necessarily imply
that mechanical arrangements should supplant manual
labour in any or in every case. The economy might
consist of doing a thing in some simpler, easier way.
Neither did it imply that direct saving might result
from the change, as savings were mostly indirect. Let
them take the following as an example. In South
Wales, collieries might be seen high above sea-level.
The miners left their homes in the valleys and climbed
the hilly roads to the shaft. They descended, and
travelled perhaps 1| miles inbye to the face. The
double journey involved at least two hours’ arduous
work per day. To young men this was perhaps no
hardship, but to men in middle life it meant a great
deal. A man was not an inexhaustible storehouse of
physical energy, and the energy wasted in travelling
had to be paid for. Either he did less work for his
employer, or had less leisure to himself than he ought.
The writer expressed no opinion as to the practicability
or desirability of conveying men from the house to the
face, and so conserving their strength. He was con-
tent to indicate the waste. Another case was that of
an unimportant drawing road in such a state that on
an average one hutch in every 10 became derailed once
in transit. If the work involved in repairing and main-
taining the road was less than that in replacing the
hutches on the rails, labour had been lessened, and he
(Mr. Gibson) called that economy, although no direct
saving might result.

APPLICATIONS TO AVOID OR SUSPEND
PATENTS.

Amongst the patents in respect of which applications
have been made to avoid or suspend are two granted to
Fritz Baum, of Herne, Westphalia, in 1903 and 1904.
An abridged description of these specifications, which
relate to conveyors and hydraulic jigging machines, is
given below.

Improvements in Conveyors for Coal, Ores, or the Like.
(No. 5483/03).—This invention relates to an arrangement
within the layer of material of separate draining devices on
a conveyor which serves for draining the goods in transit,
whereby, owing to the combined action of the sieve bottom
of the conveyor and the said devices, the draining during
transit is considerably improved. For this purpose the most
advantageous arrangement is that of drains transverse to
the direction of travel, forming draining partitions on or
in the conveyor. Each draining device may be arranged in
a separate link of the conveyor, consisting of a sieve band
with side walls. A form of the invention is shown in the



accompanying drawings. The conveyor consists of two
parallel series of links e, those of each series being con-
nected with each other and with those of the other series
by rods f, to which is fixed the wire netting g. To the
edges of the netting are fixed sheet metal side pieces h,
which are perforated over a portion of their surface i, corre-
spondingly with the meshes of the netting. The opposite
side pieces h are connected at intervals by perforated parti-
tions k, so arranged that there is a space between them for
the passage of water. By thus subdividing the conveyor
into separate pockets the material is more easily loaded,
better retained, and not washed away by the water flowing
from above.

Improvements in Hydraulic Jigging Machines (No.
21897/04).—This invention relates to a construction of
hydraulic jigger machines whereby irregularity in their
operation is avoided. According to the invention the stroke

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of the water is varied by varying the stroke of the piston or
the air pressure. For this purpose the air chamber of a
jigger machine worked by compressed air is divided by
transverse partitions into compartments, each of which has
an air inlet. The compressed air entering this inlet acts
on the jigger sieve exactly at the part which is opposite the
inlet. By admitting certain quantities of compressed air,
therefore, an adjusted pressure is obtained, which leads to
exact working, and the strength of stroke can be varied to
correspond with the requirements of the material. In
machines with pump pistons the piston space is divided by
transverse partitions into several chambers, in each of which
works a separate piston with a stroke suitable to the
material. By the invention the space above the delivery
openings is closed airtight, and provided with cocks, or
similar closing devices, by means of which the escape of the
air above the water is regulated. The slides for the delivery
of the heavy material are entirely done away with.

In the accompanying drawings two forms of hydraulic
jigger are shown as examples of the invention. Fig. 1 is
a vertical transverse section through a machine worked with
compressed air, and fig. 2 is a longitudinal vertical section
thereof. Fig. 3 is a detail view drawn to an enlarged scale.
Fig. 4 is a transverse section, and fig. 5 a part longitudinal
vertical section through a machine worked witn pump
. pistons.

Referring to figs. 1-3, the air chamber is divided, by thiee
transverse partitions e into four chambers g, each of which
has its own air inlet a, controlled by a valve b of known
kind, through which the compressed air is admitted from
pipe h. The air can be cut off by the valves c, and the
valves b are simultaneously and preferably uniformly moved
by the shaft i. The transverse partitions e extend beneath
the water level as far as the lower edge of the partition f,
that separate the air chamber from the jigger sieve k. The
water is admitted through pipe I. When the material to
be separated passes over the sieve in the direction of the
length thereof, it receives as many jerks of different force
as there are air inlets and chambers, and these jerks can be
adjusted accurately by the amount of compressed air
admitted to the chambers, so that at different parts of the
sieve the material may be subjected to different amounts
of movement of the water as may be necessary. Above the
ends of the sieve, where the material is delivered to the
screw conveyor, the apparatus is closed instead of being
left open, as in former constructions, and cocks or valves q
are provided for escape of the air which is above the water.
These cocks may be adjusted according to the nature and
the quantity of the material, so that the air may escape
more or less slowly, and thus present more or less resistance
to the rise of the water. The movement of the jigging
water is thus adjusted to produce a satisfactory operation of
the sieve. If the cock is closed the movement of the water
at this place will only be that allowed by the compressibility
of the enclosed air. The wider the cock is opened, the
stronger will be the movement of the water and the greater
the proportion of heavy material carried through the delivery
openings.

By these cocks the jigging operation may be improved
and the delivery of heavy material regulated, for, owing to
the buffer action of the air more or less confined by these
cocks, the movement of the water through the ends of the
sieve outside the slides r is not appreciably more violent
than it is through the main body of the sieve. Thus the
slide which had formerly to be fitted at the extreme ends
of the sieve to prevent too much heavy material being
delivered to the conveyor, may be now omitted. In the
present construction, owing to the fact that the movement
of the water may be adjusted within considerable limits,
and the requirements of the material may be suited, the
heavy material may be delivered quite uniformly in any
desired proportion, and the depth of material on the jigging
bed may be kept suitable without this slide, and the attend-
ance on the machine is essentially simplified. The cocks
require hardly any attention, as they are adjusted only
according to the requirements of the material, and are then
left so long as the same quantity of material is being fed
to the machine, which is generally useful. When no
material is being fed to the machine, the slide r is brought
down before the delivery openings, so that the jigging bed
is constant. This slide is, therefore, during the proper
jigging operation, entirely open, and is only entirely closed
when no material is being fed. In the form shown in figs.
4 and 5, the piston space is divided into three chambers m,
each having a separate piston nop. Each piston has a
separate stroke according to the requirements of the
material; in the drawing, for example, piston p has the
greatest, and n the smallest stroke, that of o being inter-
mediate. The adjustment of the stroke is made by means
of an adjustable eccentric or the like.



The applicants in each case are Messrs, the Simon-
Carves Bye-Product Coke Oven Construction and Work-
ing Company Limited, of 20, Mount-street, Manchester.

Mine Managers’ Examinations.—An examination for first
and second-class certificates of competency as manager and
under-manager of mines will be held on November 24, 1914,
at Edinburgh, Newcastle-upon-Tyne, Sheffield, Wigan,
Cardiff, and Birmingham. An examination for certificates
of qualification as surveyor of mines will be held at the
same places on November 25. Candidates must, on or
before October 10, send their names and state the district
in which they are employed, to the secretary at the Home
Office, Whitehall, S.W., from whom all particulars can be
obtained.