November 29, 1918.

THE COLLIERY GUARDIAN.

1135

As regards the proposals of the reports respecting
the constitution and powers of the proposed Board of
Electricity Commissioners, the municipalities recognise
the desirability of the establishment of some central
and impartial authority charged with the duty of
fostering electrical enterprise and encouraging the use
of electricity as a source of motive power in industrial
concerns.

The municipalities, however, view with grave concern,
as a dangerous extension of the policy of bureaucratic
control which has been increasingly prevalent during
the war, the proposal to confer powers which for all
practical purposes will determine the development of
electrical enterprise throughout the country upon a
small body of permanent officials, who will be supreme
over all existing and future electricity undertakings,
appointed by the President of the Board of Trade
without reference to any superior authority, three of
whom will bold office subject only to an age limit, and
two of whom will be appointed for a short term of
years.

A small body of technical experts, however eminent
individually, is, in the view of the municipalities, unfitted
to be entrusted with autocratic powers of the character
proposed, and the central electrical authority should be
so constituted as to be directly susceptible to the
influence of public opinion and should comprise a
sufficiency of members of independent judgment and
general experience.

It is essential that any such central electrical autho-
rity should be free from partisan bias.

The fit st Board of Electricity Commissioners should,
it is submitted, either be appointed directly by Parlia-
ment, or be constituted in accordance with directions
given by Parliament so as to secure an impartial and
judicial body, and the appointment of its constituent
members should not be left to the absolute discretion of
the President of the Board of Trade.

With respect to the delimitation of electrical districts
and the constitution of district boards, all the facts are
ascertainable immediately, and these questions, it is
submitted, should be disposed of by direct Parlia-
mentary action after preliminary local enquiries. In
no case should the decision on matters of this character
be left in the disposition (whether by Provisional Order
or otherwise) of a small body of experts as contem-
plated by the report of the Electric Power Supply
Committee.

Opposed to Monopoly.

It is unreasonable that any embargo should be
placed upon extensions of existing electrical under-
takings, whether by the erection of new stations, or
the extension of existing stations, during any interval
which may occur before the suggested super-power
stations are in a position to supply power, especially as,
instead of the 4 4 temporary lull in manufacturing output
immediatoly after the war ” contemplated by the Coal
Conservation Sub-Committee’s report, the commercial
necessities of the situation may then, on the contrary,
as is apparently recognised by the Electric Power
Supply Committee, more probably demand an imme-
diate increase in the supply of electric power, which,
the municipalities submit, can be effected quickly and
economically by enlargements and extensions of the
plant of existing undertakings.

The municipalities have already commented upon
the pronounced anti-municipal bias of the Coal Con-
servation Sub-Committee’s report, and upon the fact
that its conclusions, if adopted; will directly tend to
consolidate and strengthen the monopoly in the north-
east coast area of the Newcastle-upon-Tyne Electric
Supply Company Limited, and its allied and subsidiary
companies. This bias, while not so directly expressed
in the report of the Electric Power Supply Committee,
is none the less present therein, and the municipalities
fear that if its proposals are put into effect the result
in the north-east coast area will be that the generation
and supply in bulk of electricity may well pass from the
municipalities, and that the north-east coast group of
companies will be left to continue their operations either
on their own account or as lessees from the district board.

The municipalities further direct attention to the
inequitable character, so far as regards municipal
electrical enterprises, of the financial proposals of the
report.

It is apparently proposed that the generating stations
and distribution systems of municipalities shall be
taken over by the district electricity boards, on terms
which imply no more than the bare discharge of out-
standing loans by means of terminable annuities to be
used by the local authorities in discharging their loan
obligations, no cash payments or issue of electricity
stock being involved in their cases.

The basis of compensation proposed by the report
will act unfairly as between municipalities and com-
panies, and will have the effect of penalising those
undertakers who have set up adequate reserve funds
and maintained their undertakings in an efficient
manner, and of favouring those undertakings which
have distributed an undue proportion of their surplus
revenues amongst shareholders, or in the reduction of
rates.

Terms of Transfer.

It is submitted that if electricity boards are to be
constituted to take over existing electrical undertakings
the terms of transfer of municipally and commercially-
owned generating stations and distributing systems
should proceed upon the same basis, and that whatever
terms are given to the one should be given to the other,
so that in the case of a municipally-owned undertaking
the capital of the undertaking should accrue to the
municipality which has borne the risk and responsi-
bility of the undertaking in the past.

Again, the municipalities object to the recommenda-
tion of the Electric Power Supply Committee’s report,
that whereas commercial distributors of electricity are
to continue to exercise the right of paying dividends to
their shareholders, subject only to the limitations of a
sliding scale of charges to consumers, municipalities
who continue to distribute electricity are to be permitted
either to make no profit at all or only a nominal profit.

Furthermore, the municipalities take strong exception
to the proposal that district electricity boards or their

lessees should be empowered to supply high-tension
electricity in the areas of municipal distributors of
electricity, and it is contended that, with the possible
exception of electricity used by railway companies for
traction purposes, there thou Id be for each local area
of supply a single distributor of electricity regardless
of the question whether the energy supplied is low-
tension or high-tension electricity.

Finally, it is manifestly inequitable that power
supply companies (whose areas of supply for power
happen to be reduced by the district electricity board,
to cut out districts which can be better served from
other districts) should, to the exclusion of municipali-
ties (who may apparently be subjected to similar
reduction of their areas of supply), have conferred upon
them, as is proposed by the Electric Power Supply
Committee’s report, the right of supplying electricity
for lighting purposes in places where there is at the
time no lighting supply.

The municipalities do not concur in the proposals of
the Electric Power Supply Committee’s report that a
preferential basis of rating should be accorded to
electricity transmission mains, and that existing
restrictions as to the use of overhead lines should be
removed.

Public Ownership.

With respect to the former, the municipalities, not
only as owners of electrical undertakings, but in respect
of their tramways, main sewers, and other assets, have
borne in the past their proportion of local rates, and
they see no reason why differential treatment should
be extended to electricity transmission mains to the
exclusion of other analogous ratable hereditaments.

As regards the latter, while in rural areas, and as a
temporary expedient, the use of overhead lines for the
transmission of electrical energy may be in special
circumstances desirable and even necessary, a general
concession of this character in urban areas is to be
deprecated.

The municipalities observe with satisfaction that the
Electric Power Supply Committee’s report recommends
that in the national interest generating stations and
main transmission lines ought, as a general rule, to be
publicly owned, and they submit that the district
electricity boards should, in all cases, be so constituted
as to be wholly independent of the influence or control
of commercially-owned electrical enterprises. To secure
this object, it is strongly urged that the district electri-
city boards should consist of representatives of local
authorities and large consumers to the exclusion of
companies generating electricity.

In conclusion, the municipalities view with the
gravest misgivings the manifest dangers presented by
the recommendations of the reports of the establish-
ment in the north-east coast area of an electrical
44 trust ” exercising with Parliamentary sanction para-
mount powers in that area with respect to the produc-
tion and supply in bulk of electricity. They, therefore,
most earnestly request that before any proposals are
submitted to Parliament, based upon the reports, his
Majesty’s Government will institute a complete and
exhaustive enquiry, by some competent and independent
authority, in order that accurate data may be forth-
coming as to the statements and findings contained in
the reports, and that no affirmative action be taken
until an adequate opportunity has been afforded to the
municipalities of presenting their views before an
unbiassed and impartial committee of Parliament.

DIRECT-CURRENT ARMATURE TROUBLE.

By Frank Huskinson.

A peculiar case of trouble with a direct-current
armature that will be of interest to those having to do
with electrical work at the mines, came under the
author’s notice recently. The commutator of a 25 horse-
power direct-current armature was removed for
rebuilding. The connections were marked so that they
could be put back in the same position as before, to
save the time of testing them out.

After reconnecting all the leads, a bar-to-bar test,
made with a millivoltmeter, showed all connections to be
in order. The machine was then assembled and put
into service on a pump. The motor seemed to run all
right, but showed an increase of speed of at least
15 per cent, over what it had run when driving the same
pump previously. After running about half an hour,
it was noticed that the armature had developed an
excessive amount of heat, not confined to any one
point, but uniform all over the armature and com-
mutator.

Further tests were made, and all connections as well
as the voltage were found to be all right. Several
trial runs, however, gave the same results as before,
the armature and commutator heating up excessively.
Commutation seemed to be good, as there was prac-
tically no sparking of the brushes and the commutator
had been undercut.

Finally, it was decided to remove the armature and
give it another bar-to-bar test with the millivoltmeter.
The result was the same as before. All the leads were
thereupon removed from the commutator and a rotation
test was made, with the result that at one point the leads
were found to have been interchanged so that the top lead
of an adjacent commutator bar had been connected
with the top lead of the next bar, whilst the bottom
lead of an adjacent commutator bar was connected
with the bottom lead of the next bar. This resulted
in the windings being split at this point, putting them
in series-multiple instead of straight series.

This armature was connected up to operate in a six-
pole machine, and the motor was fitted with six brush
holders. It was a compound-wound, 220-volt interpole
machine. The action of the millivoltmeter in showing
all connections O.K. can readily be explained. The
current for testing was taken from a bank of lamps in
series with only a small portion of the coils on the
armature at a time. If the testing current had been
used through one-half of the armature at once, it
would have have shown up this trouble; but the fact
that the armature was for a six-pole machine was not
even considered.—Coal Age.

LETTERS TO THE EDITORS.

The Editors are not responsible either for the statements
made, or the opinions expressed by correspondents.

All communications must be authenticated by the name
and address of the sender, whether for publication
or not. No notice can be taken of anonymous
communications.

As replies to questions are only given by way of published
answers to correspondents, and not by letter, stamped
addressed envelopes are not required to be sent.

THE THEOREM OF PYTHAGORAS.

Sirs,—The above theorem lies at the root of much of
our geometry and trigonometry, and anything that
facilitates the knowledge and understanding of.it has,
in consequence, a distinctly educational value. The
new proof—if it is actually new—which I now give of
the truth of the theorem (Euclid i., 47) is much simpler
than any I have been able to find elsewhere, and
although I had a strong temptation to reserve it for my
own private pupils, I concluded that it would be more
in accordance with the spirit of the New Democracy to
make it public.

It may be that the proof is not actually new. If it is
not, I can only say that it suggests something very like
a conspiracy on the part of our educational authorities
that the proof should not be generally known and that
it should be absent, so far as I can gather, from all the
standard text-books. One thing is certain—viz., that
the proof would not be admissible from the standpoint
adopted by the authorities of Cambridge University in
1888. For although most of the proof follows from
Euclid, Book i., Props. 5, 32, it is clinched by the
44 Principle of Similar Triangles” only, which is not
treated in Book i., but which, on the other hand, is a
principle perfectly obvious to every schoolboy who has
mastered simple proportion.

Having now placed the case on its proper basis by
showing that my proof presupposes nothing more than
a knowledge of Euclid i., 5, 32, and a very elementary
knowledge of simple arithmetic, I may state it as
follows:—

Theorem.—In a right-angled triangle, the square on
the hypotenuse is equal to the sum of the squares on
the other sides.

Proof.—Let ABC be a right-angled triangle having
the right angle ACB.

*g>

With A as centre, and radius AB, describe the circle
DBE. Produce AC both ways to meet the circle at
D and E. Join EB and DB. Then :

From Euclid i., 5, 32, and the 44 Principle of Similar
Triangles,” it follows that:—

“ = JO; the,.tore,
Jov JtLL/

BO2 = DC x EC

= (AD - AC) X (AE + AC)

= (AB - AC) x (AB 4- AC)

= AB2 — AC2, from which
AB2 = BO2 + AC2.

If this is not a new proof, it is at least the easiest
proof, and the most commonsense proof, of the
Pythagorean theorem I have ever seen.

H. W. Halbaum.

177, City-road, Cardiff,

November 19, 1918.

Coal Controller Still Urges Economy.—Speaking at a
Fuel Economy Exhibition in London on Monday, the
Coal Controller said he had been frequently asked why
he still persisted that it was necessary that there should
be rigid economy in the consumption of coal. His answer
was that the armistice was not peace. It was not possible
to get the miners back from the Army at once. Every
effort was being made at the present time to do so, but
it must take time. We had still to supply our Allies
with coal. Simply because the paint had been washed
from the street lamps and people were not prosecuted for
showing a little extra light from their houses, we must
not think that economy in coal was any the less essential
than it was a month ago. The moment it was possible to
increase the ration of coal and electricity it would be
done, but meanwhile we had to be absolutely firm and
determined to economise in our fuel consumption in every
possible way. Sir Guy Calthrop added that during the
week of armistice 2,000,000 tons of output were lost owing
to celebrations by colliery workers.

The Damaged French Coal Mines.—The latest news
received by the French Coal Mission in London shows the
character of the damage done to the coal mines of Northern
France by the Germans. By means of dynamite, the
metal tubbing through the water-bearing strata of the
Nord coal field was destroyed, and torrents of water
poured into the workings. Then the shafts were blown
in. The surface structures, winding gear, pumps,
engines, boilers and other surface plant have been wrecked
or carried off into Germany. The tale of wreckage which
has reached the French Mission confirms the estimate of
M. Loucheur, the French Coal Controller, that it may
take, according to the measure of destruction, from two
to five years to restore the coal production of the wrecked
mines. British Forces have entered the great Mons-
Charleroi coal field, and the Belgian Coal Department in
London is anxiously awaiting information as to whether
the Germans have given heed to President Wilson’s warn-
ing. Even if the mines have been spared, there is no
hope of Belgium having any surplus of coal to give to
France in the immediate future.