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ilp archive : journals
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public lighting no. 8 vol. 2
December 1937
- Editorial p103
- Greetings
- Festive greetings and general hopes for 1938.
- A Move Forward p103
- A discussion took place at the Public Works Congress at the Agricultural Hall,
Islington by members of the APLE to discuss the Departmental Committee's final
report. A great deal of useful discussion took place with the object of clearing
up obscure points and of determining on a course of action by the
Association. The meeting included Dr. C. C. Paterson and Mr. J. F. Colquhoun of
the Departmental Committee and Mr. F. C. Smith, Mr. J. M. Waldram and Mr. G. H.
Wilson who were technical advisers to the committee. The meeting was passed
with the following resolution which was moved by Mr. E. C. Lennox and seconded
by Mr. T. Wilkie:
That this Meeting submit thanks to the Minister Of Transport for the Final Report
issued by his Departmental Committee on Street Lighting and in expressing its full
appreciation of the valuable recommendations it contains, urge that early
consideration be given by him to such amendments on administration controlling the
public service of Street Lighting as will enable the recommendations to be
carried into effect.
- Main Roads p103
- The Minister of Transport has made an important announcement in Parliament
with reference to financial assistance from the Government to local street
lighting authorities responsible for main traffic routes. They will pay
50% of the expenditure both capital and maintenance. This is for trunk
roads only. It is to be hoped that this will not mean a comparative neglect
of the side roads leading to this thoroughfares; effective grading in the
lighting from main to side roads should form a constituent part of any
improvement scheme.
- Wanted, a Campaign p104
- Of the fifteen recommendations in the Final Report of the Department Committee on
Street Lighting, three only contain a reference to finance. The first example,
that of the period of lighting from dusk till dawn, the recommendation is qualified
by the practicality of "financial consideration." The second example is
the recommendation which relates to the raising the level of inadequately lighted
traffic routes which is subject to "financial conditions permitting." The third
instance is the consideration "that the cost of lighting roads should be aided
by grants from National Funds administered by a responsible Government
Department." Surely the time has come for a concerted movement by all the
associations interested, to start an organised campaign which would have
for its object the recognition by the Government of the fact that street lighting
and public safety are inter-related and no substantial advance is possible by
local authorities without recourse to the National Exchequer.
- String Lighting p104
- Lighting specialists who foregathered at the Manchester conference recently
convened by the British Electrical Development Association (BEDA) and the
Electric Lamp Manufacturers Association (ELMA) had a very useful experience.
Events included a discussion on the merits of staggered lamps versus central
suspension, a night inspection of various installations and demonstrations of
most types of illuminant. The practice of switching off street lights during
the night was criticised by several speakers. Perhaps the most striking suggestion
was a system under which a cable passed overhead and being switched on, gave
a continious light - a kind of string lighting.
- Lighting Main Roads p104
- Report of the discussion in Parliament.
- Lighting: Distribution, Lighting: Funding,
Lighting: Legal, Lighting: Specifications.
- Electric Installation At Chelmsford p105
- On Monday, 13th December, The Mayor, Councillor J. T. Bellamy J.P.,
performed the "switching-on" ceremony of the latest installation of
Mercra and Mazda lamps in Chelmsford.
The town's street lighting by electricity goes back to 1887 when, on the
occasion of Queen Victoria's Jubilee, an installation of arc lamps
was provided by Crompton And Company who were the original
suppliers of electrical energy in the town, and by whom supply was made available
to ordinary consumers in 1890. In 1892 a system of street lighting was
introduced consisting of arc lamps erected on wooden poles and supplied
by 1100V DC. On the granting of the first Electric Lighting Order in 1894
to Messrs. Crompton, which was tranferred to the
Chelmsford Electric Lighting Company the following year, the street lighting
by electricity was maintained and in 1905 the original arc lamps were
replaced by the flame arc type, whilst the side streets were lighted by
means of 32 candle-power carbon lamps suppled at 110V AC. In 1907 the
undertaking was transferred to the Chelmsford Electric Supply Company Ltd.
and in 1919 the existing arc lamps were replaced by metal filament lamps.
In 1934, the electricity supply undertaking was transferred to the
County Of London Electric Supply Co., Ltd..
- The complete installation comprises 824 BTH
units covering approximately 40 miles of lighted thoroughfares.
- Main Roads
- 187 Mercra 400W and 250W in BTH
Dilen lanterns with BTH control gear
were installed along the High Street, Moulsham Street, London Road,
Duke Street, Tindal Square, Springfield Road, Baddow Road,
Rainsford Road, Broomfield Road, New Street, Rectory Road and at principal
road junctions. The poles are arranged in a staggered formation, ranging
from 120' to 150' while the lanterns are mounted at a height to conform
with modern standards. The centre of the town is lit to Class "D" while
Duke Street and parts of London Road are Class "E" and the remainder in
Class "F."
- Side Roads
- 637 BTH County Junior lanterns with 150W
Mazda gasfilled lamps are used for the lighting of the side
streets, the majority being fitted at existing positions. For the remainder,
additional columns have been provided in some of the more important
residential areas to increase the standard of lighting. 19 of these lanterns
are fixed to special brackets fitted to company service poles carrying
overhead transmission lines and 8 are used in conjunction with wall brackets.
- Lighting Hours And Maintenance
- The lamps are controlled by Solar Dial Time Switches and are in
commission daily throughout the day - those in important positions and road
junctions being lighted from dusk until dawn and the remainder from dusk
until 1AM. The County Council is repsonsible for the general maintenance.
This new installation affords increases in illumination of 100% in the main
thoroughfares, 50% in the principle side streets and 33% in the remainder
while generous lighting is afforded at the more important road junctions.
- Lighting: History,Lighting: Installations
- Reflecting Road Studs p105
- The City Of Leeds have installed in the Otley Road a novel system of
road studs (cats eyes). The lines have been laid in Otley Road, Leeds,
commencing at a point on the outskirts of the city where street lamp
illumination ends, to the city boundary, a distance of three-quarters of a
mile. By day the line is clearly indicated by the yellow pads and by
night the line is brilliantly illuminated by the reflected light of
vehicle lamps. The road stud consists of a cast-iron well base into which
is inserted a flexible rubber pad fitted with four crystal lenses, two
lenses on eitehr side of the pad. Traffic passing over the studs compress
the rubber pads to ground level and in doing so the lenses are
automatically cleaned by a rubber wiper.
- Lighting: Installations, Other
- Warning Signals On Road Works p106
- Details of a scheme suggested by the West Riding Highways Committee
which was written in a letter by the County Surveyors' Society to the
Executive Committee of the County Councils Association. It is a continuation
of correspondence from August 1936. The suggestion is to illuminate the
standard 'stop' and 'go' signals at night, and whether the Ministry of
Transport would be prepared to issue regulations which would be prepared
to issue regulations which would be applicable to the country as a whole.
The MOT have replied that the standard signs are authorised for
use in all parts of the country and that they may be illuminated but the
County Surveyors' Society want it to be mandatory.
- Other
- Catalogues And Booklets p106
- The BCGA have issued a booklet called
Light On The Roads; Holophane have issued a new
catalogue illustrating their reflectors and lanterns; Horstmann
have produced a new booklet of the loose leaf type; the GEC
have issued a comprehensive catalogue dealing entirely in Ironclad
switchgear; Siemens Electric Lamps And Supplies Ltd have issued
a revised catalogue dealing with ZED Cartridge fuses and Ironclad switch and
fusegear.
- Lighting: Publications
- The Sangamo Type SS Time Switch p106
- Details of this time switch which has been designed to combine the
requirements of a wide range of switching applications.
- Lighting: Control
- Sheffield Illumination Society p106
- Mr. J. F. Colquhoun, Public Lighting Engineer, Sheffield Corporation,
addressed the members of the Sheffield Illumination Society on
"Some Aspects of Street Lighting." Details of some recent improvements in the
lighting of Sheffield streets, road safety without the use of motor car
headlights and the angle separation system evolved for the lighting of bends
were discussed. It was pointed out that there was no one distribution of
light suitable for every kind of road. Mr Colquhoun urged that a great deal
could be done by providing light backgrounds. For traffic routes and busy local
thoroughfares lamps 25' high using 5000 lumens per 100 linear feet were
recommended. Other roads could be lighted efficiently using posts 13' to 15'
high and in such a way that those acquainted with the area would find the use of
headlights unnecssary. Colquhoun also said that he would have to be convinced there
was a saving using sodium or mercury lamps before he would use them. With
electricity at the price he was able to obtain it, there was no saving. Following
the meeting, two sound films, "Planned Street Lighting" were shown. These were
provided by BTH.
- Lighting: Installations
- Centralised Control Of Street Lighting: The Actadis System Installed At Maidstone p107
- The street lighting in Maidstone was "switched on" from a centralised
control panel by Mr. J. M. Kennedy, O.B.E. before a representative gathering of
Lighting Engineers. The system was the Actadis ripple control, which is a revolutionary
departure from all existing methods of controlling public lighting and certain
other types of load. With the Actadis system an unlimited number of circuits
can be controlled simultaneously from a single distant point. The system
conveys a high frequency signal "ripple" from a transmitter located in the generating
station to relays located in the low tension networks. By use of ripples of
different frequency, the transmitter in the central station can operate relays
selectively; one frequency can turn street lights on, a second frequency can
turn them off, a third frequency may switch off-peak loads on, a fourth
frequency may switch them off, etc. Ten to twelve different frequencies can
be supplied.
- The transmitting apparatus in the central station is controlled by push
buttons. The ripple signal passed through the high tension feeders and substations.
It is received by Actadis relays, situated in lamp columns or in consumers'
premised (for the control of off-peak loads and other services). Although the
system may be novel to British engineers, Actadis installations have been in
operation in other countries since 1928, and large installations are in daily
service all over Europe.
- In the past few years a continuous succession of large Actadis installations
has demonstrated that, of all possible systems of public lighting control, the
Actadis system (although not always the cheapest in initial capital cost) is
among the best, since it complies with every possible requirement which the
street lighting engineer can make of it.
- The features are:
- The street lighting of a whole city or any section of a city can be controlled
by a single push button in the generating station.
- This control is effected without pilot wires and the street lamps are
fed directly from the network, just as if time-switches were used.
- Apart from day-to-day service, public lighting can be instantaneously
extingushed or relit from a central point at any time of the day or night
in an emergency of fog or war.
- An Actadis ripple transmitter can be operated either by push-button,
by single time-switch or by a single photo-cell.
- There are between 50 and 100 installations, some in the largest cities
in Europe. On average, it is found there is about one failure, from all
causes, in every 50,000 operations. As a relay is not continiously working
and only operates for a few seconds per day, mechanical wear need not be
considered. In estimating annual costs, Actadis relays can properly be written
down over fifteen or twenty years and will operate without expensive maintenance.
- Lighting: Control
- Defying The Elements - BTH Lighting Equipment In Hong Kong p108
- A typhoon in Hong Kong on September 2nd, measured at 164MPH at North Port,
caused all sorts of "slight damage" including street lights. In some cases, many
of the lanterns disappeared altogher. However, the BTH lanterns
containing Mercra lamps on Kings Road, which were supplied two years
ago, "sood up wonderfully; beyond a little glass broken and a few lamp failures
there was nothing wrong with them - this is the second typhoon these lanterns
have stood up to and I think this is a tribute to their construction."
- Lighting: Installations
- The Late Captain E. M. Severn p108
- Obituary of Captain Ernest Michael Severn. He entered the services of
the South Metropolitan Gas Company as a junior clerk, where
he eventually became superintendent of public lighting, in which capacity he
had to deal with the public lighting of at least nine of the London boroughs.
His service with the company extended over 46 years. He was one of the founders of
the APLE, being its first honaray Treasure and later President in 1933.
- Lighting: Personnel
- The Final Report - Uniformity And Bigger Administrative Units p109
- Two years have passed since the Interim Report of September 1935 of which Mr.
J. F. Colquhoun, Public Lighting Engineer, Sheffield, was a member. Among the fifteen
recommendations contained in the Report, perhaps the most urgent are those which
state "that there should be reasonable uniformity in the lighting of portions of
traffic routes presenting similar characteristics," and that larger aministrative units,
aided by national grants, are a necessity if effective progress towards this ideal is to
be made.
- A Whole-Time Engineer
- Another very important opinion, which was embodied in the intermin report, was
that "lighting authorities should be advised by an engineer competent to deal with
street light." A whole-time specialist should be appointed by the larger or more
important areas, or in those districts which do not warrant a full-time job, the engineer
to the lighting authority should've made a special study of street lighting.
- Extraneous Lights
- The committee reiterate their previous conviction that there should be
definite power given to local authorities to control extraneous lighting, in so far
as such may be seriously detrimental to the light in street lamps. An allied
recommendation deals with the necessity to avoid possible interference with railway
signals and the need to keep in touch with the railway companies before installing
street lighting in their vicinity.
- Four Functions To Be Fulfilled
- Street lighting has four functions to fulfil: it has to meet the daily needs of
road users, the police and local residents, and also to serve various special purposed
in shopping areas and important urban centres. Most of the chief problems facing
Public Lighting Engieners arise out the needs of the traffic, and continual growth
of motor traffic has made this problem much more complicated and more urgent.
- Two Groups Of Roads
- After full considersation, the Committee came down on the side of a broad
classification of roads into two groups: (A) "traffic routes" and (B) "other roads."
Group A roads were those where the standard of lighting provided an ample margin of
safety for all road users without the use of headlights by motor vehicles.
- Technical Chapters
- Parts IV to XIX of the Report deal with technicals aspects of street lighting.
- Circular 504
- On the 2nd November, concurrently with the publication of the Final Report,
the Minister of Transport issued Circular 504 (Roads) in which he draws the attention
of local authorities to the final report. The Minister expresses his confidence that
a local authority, when considering the installation or improvemetn of street lighting
systems, will pay regard to the important technical recommendations contained in the
Report. The Circular adds that the only power which the Minister possesses to
contribute from central funds towards the expenses incurred by lighting
authorities is that conferred in certain cases by Section 6 (4) of the Trunk Roads
Act. The Act does not apply to the County of London.
- Recommendations
- The recommendations are then reproduced in full.
- Lighting: Specifications
- A Question In Parliament p110
- On the 17th November Mr. Lyons asked the Minister Of Transport what steps
he proposed to take on the recommendations in the Final Report. The Parlimanentary
Secretary responded that the report had alraedy been brought to the attention of all
local authorities by Circular 504. He hoped that all the authorities would put the
recommendations into effect.
- Lighting: Specifications
- New Methods Of Road Lighting - Some Recent Developments in France p111
- Description of new street lighting installations in France.
- The simplest type of street lighting unit is a cruciform standard
12'-15' high set on a square base
in sheet iron in which the contacts and connections are placed. The lantern
is a spherical glass globe divided into two parts. Inside the globe is the lamp
with a prismatic refractor designed to give either a longitutindal or
circular dispersion of the light. Above a 500W incandescent lamp is horizontal
280W mercury vapour lamp which has its light directed upwards and is intented
to illuminate the trees. In some standards the base of the lamp is built with
small projectors throwing their light upwards and outwards and lighting
up the standard itself; others are designed with discharge tubes in blue
light to stress the vertical lines. These lights give a very interesting
decorative effect and their installation in Paris has proved very popular.
- Saulnier Duval Frisquet have brought out a lantern for rural road lighting
with a view to a more even distribution of light over the road surface. The
apparatus consists of a lamp provided with a symmetrical reflector to either side
of which special reflectors are fitted. These are long tubes which project
from the sides and have a profile designed to reflect the light of the lamp
on to the road in a series of vertical planes parallel with the axis of the road.
These lamps are placed with their axes at right angles to that of the road and
their spacing is calculated so that the bands of light overlap to give an even
brilliancy on the road surface.
- A different idea is that of the Forclum Photostrade lamps. These depend on
the fact that the greatest brilliancy of the road is obtained from rays of light
which strike it at an angle approaching 90°. To obtain this, the apparatus
consists of a very low base in concrete with an internal chamber to provide space
for a small transformer. On the top of this base is a cast-iron hood in which is
fixed a light similar to an ordinary motor car headlight. The light is arranged
so that its rays are cast on to the road at a distance of about 30', so that the
rays hit the road at an angle varying between 85° and 90° from the
vertical. The lights are staggered on either side of the road and their reflectors
are regulated so that alternate reflectors on opposite sides of the road
produce intersecting beams. The lamps run at 12V, 70W.
- Lighting: Luminaires, Lighting: Distribution
- New Lighting For Barwell p112
- Brief description of the new installation in Barwell.
- Lighting: Installations
- Hackney Installs First Luminescent Street Lighting p112
- Brief description of the new installation in Hackney.
- Lighting: Lamps, Lighting: Installations
- Increased Demand For Clock Controllers p112
- The Horstmann Gear Co., Ltd. report another record year
in all branches of their activities. The additional demand for Newbridge Controllers,
Comets and Time Switches has necessitated the aquisition of
large additional works. The Comet has been particularly successful
and has been adopted by numerous public authorities and gas undertakings.
- Lighting: Control
- Improved Lighting At Ealing p112
- Brief description of the new installation at Ealing.
- Lighting: Installations
- Place De La Concorde - An Interesting Experiment In The Heart Of Paris p117
- The Place De La Concorde is one of the largest open spaces in any city in
the world. The lightign is provided by 212 gas standards on mountings of 13'. Modern
requirements demands still better lighting: but increasing the height of the existing
standards wouldn't be appreciated from an aethetic point of view; and increasing the
brightness would increase the glare. Therefore telescopic electric lamp pillars were
used. Ten have been installed on the outside board of the Place. Each is 100' in height
and support six 1500W incandescent lamps which are housed in an upright cylinder
of 12' in height and placed at the top of the telescopic column. Each lamp is placed
within a reflector of silvered prismatic glass which shines out across the Place.
The lamp standards are constructed of four steel tubes. An sunset, by control of
the Actadis system, the lamp is extended upwards to its full height
and the lamps are lit progressively. The telescopic lamp standards were supplied
by Le Tube d'Ocier and the lenses and lanterns were constructed
by Holophane.
- Lighting: Distribution, Lighting: Luminaires, Lighting: Installations
- Ovecoming Colour Difficulty p118
- The three principle ways of improving the colour rendering of
mercury discharge lamps are:
- The addition of cadmium and zinc to the mercury of the inner tube.
This lowers the efficiency from 45 to 37 lumens per watt but gives
approximately 2½% more red rays.
- The combined electric dischage tube and tungsten filament. It gives
approximately 8% more red rays but the efficiency is only 25 lumens per watt.
- Lamps with Fluorescent Powder Coating on the outer bulb. The standard
mercury lamp inner tube is enclosed in a larger outer bulb than that used
for standard lamp types. The interior surface of the bulb is coated
with a substance whcih becomes fluorescent under the action of ultra-violet
waves and converts this energy into visible light. The initial efficiency
is 38 lumens per watt with a red ratio of 5-6%. In modern street lighting,
control of the light output is a matter of first importance and lanterns
used for use with electic discharge lamps are designed to distribute
correctly a comparatively narrow cord of light. However the outer bulb
of this new lmap becomes the light source presenting an extremely difficult
problem in light control. A directional lantern designed for standard
mercury discharge lamps will give nothing like such an efficient
performance if used with fluorescent lamps.
- Lighting: Lamps
- New 400W Osira Luminescent Lamps p118
- A new Osira high pressure mercury vapour discharge
lamp has been introduced by the GEC. The new lamp
has been designed with consideration for the colour of the light
given - the luminescent powder coating on the inner side of the outer
bulb converts invisible ultra-violet rays into visible rays at the red
end of the spectrum. The lamp is made in a cone-shaped isothermal
bulb and also in a tubular bulb for use in certain street lighting
lanterns where dimensions will not accomodate the cone shaped bulb. It
was developed for industrial lighting to fulfil the need where
colour discrimination is essential, but it also has an important
application in street lighting for promenades, bus and coach stations,
quaysides and landing stages. It can be used in existing 400W
Osira circuits.
- Lighting: Lamps
- Leicester p118
- Brief description of the new installation in Leicester.
- Lighting: Installations
- Dublin's White Way - An Experimental Mile Of Lighting p119
- A mile of Merrion Road has been lit experimentally to meet traffic conditions:
very heavy, continuous and fast and includes buses and trams. The route is lined
on each side by tramway standards and these have been used as lamp standards.
The thoroughfare averages 64' wide and is comprised of a roadway 38'6" wide
with a pathway 12'9" on each side. Brackets with a projection of 6' towards
the centre of the roadway are mounted on the tops of the tram standards above
the span wires. Each bracket is fitted with a four-way adjusting device which
permits the mounting of lanterns truly vertical over the road surface irrespective
of the setting of the standards in the ground. The lanterns are mounted opposite
each other across the roadway and the average spacing is 121'. The average height
of the light sources is 25'6". Each lantern is fitted with a 300W incandescent
filament lamp. The lanterns cut off all light within 20° of the horizontal
plane. They have a well ventilated canopy and body of sheet copper enclosing
a single-piece silvered mirror dome reflector with refracting prisms on the
outer and silvered surface of the glass. The lantern is open at the bottom and
includes no glassware other than the reflector. Focussing is controlled by a
single eternal thumbscrew and the lamp filament can be moved not only in a
vertical plane but alos in a horizontal plane. The illumination on the road surface
averages 1.0 F.C. under the lighting units and 0.33 F.C. at the test point, giving
a diversity in illumination of 2.8 : 1. The diversity of brightness is greater
than the diversity of illumination and is visible to the eye - this does not
effect "visibility". More even brightness can be obtained by altering the focus
of the lamps byt the introduction of a more high angle light inevitably increases
the brightness of the units and gives rise to a complaint of glare. The concensus of
public opinion is that adequate "visibility" is provided for all normal usage of
the road and that the variations in road surface brightness are infinitely preferable
to even the smallest degree of glare.
- Lighting: Distribution , Lighting: Installations, Lighting: Luminaries
- County Councils Association Considers MOT Report p119
- Last year the Association decided not to offer any objection to the
Interim Report and they have now approved the following resolutions in the
Final Report:
- The Highways Committee do not with to offer any objection, but before
expressing a final opinion, they want to hear from the County Surveyors' Society
on the subject.
- The committee regret the apparent omission from the report of any reference
to the Association's previous observations regarding the danger and confusion
caused on roads at night by the widespread use of coloured lights, especially
on premises in proximity to traffic signs and signals.
- The recommendation that lighting authorities should be empowered to
control extraneous lighting should be extended to cover such extraneous lighting
as may endanger traffic.
- Lighting: Specifications
- Light Actuated Control p120
- Paragraph 96 of the Final Report states "that street lighting should be
continued from dusk to dawn." The only method that can completely comply with
this recommendation is light-actuated control. Mr. D. M. Kinghorn, A.M.I.E.E., the
Borough Electrical Engineer of Southwark, was one of the first to realise
the value of this type of control and has been installing light-actuated
control units for a number of years. (Includes picture).
- Lighting: Control
- Silhouette Lighting p120
- A new type of gas lamp is to be used for the first time in London
for modernising Paddington's main street ligthting. 73 Maxill
lamps will be erected in Praed Road, Porchester Road, Queen's Road,
Westbourne Grove, Clinton Road and Carlton Vale, and they will
be mounted 120' apart and 25' high. The effect will form a bright
background against which pedestrians, motor cars and other traffic
will stand out clearly as silhouettes. The existing lamps will
be transferred to Elgin Avenue and Sutherland Avenue to replace
smaller lamps.
- Lighting: Installations, Lighting: Luminaires
- New 400W Osira Luminescent Lamps p120
- Pictures of the cone-shaped and tubular versions of the lamps.
- Lighting: Lamps
- Air Raid Precautions p120
- There has been much discussion recently on the subject of
air raid precautions by local authorities and Government Departments.
Street lamps must be dimmed or extinguished at a moment's notice.
The Gas Meter Company, Limited are announcing a
an emergency control device which will allow street lighting to
be extinguished. The device might also serve as an air raid warning to
gas consumers because of the reduction in pressure. At a reduction in
pressure he gasway is closed, but an adjustable leak is allowed which
supplies sufficient gas to keep a small flame at the nozzle of the
burner without illuminating the mantle; thus when pressure is again
increased to normal, street lighting comes into operation again.
- Lighting: Control
- Improved Gas Lighting At Keighley p121
- Report of the new gas lighting installation at Keighley. Includes picture.
- Lighting: Installations
- New 400W Mercra Luminescent Lamps p121
- Wherever colour discrimination is required, modern mercury vapour
has disadvantages. The spectrum of the standard Mercra
lamp is rich in blue, green and yellow light, but deficeint in red light,
which is only 1-2%. The new lamp consists of a inner glass envelope containing
mercury and cadmium. The inside wall of the special outer jacket is coated
with a powder with fluoresces strongly under ultra-violet radiation and
produces visible red light from the previously wasted energy. The electrical
characteristics of the lamp are similar to those of the standard 400W
Mercra, the same standard choke and condenser equipment
being necessary. As fluorescent powders show a decrease of efficiency
during life if they are operated at too high a temperature, the
outer envelope of the Mercra fluorescent lamp is considerably
larger than that of the standard Mercra lamp and has been
specially designed to ensure an even temperature distribution over the
fluorescent surface. The fluorescent coating acts, to some extent, like
a pearl bulb and diffuses the light. Optical re-direction of this
light by special lanterns is difficult due to the size. Therefore the
lamp is specially suited for industrial lighting. For street lighting
perfect colour rendering, although aesthecically desirable, is not
essential, and that the fluorescent lamp is not intended for
general street lighting. The new lamps are made in two types: iso-thermal
bulb type and tubular bulb type. The tubular bulb type is intended for
use in existing street lighting lanterns.
- Lighting: Lamps
- Correspondence p122
- A Reflection From Folkestone
- In the paper Some Further Experiments In Street Lighting,
Dr. English and Mr. Stroud show under conditions of their test
that 75° gives a minimum glare figure - the test had been arranged to show
the 75° beam to advantage as the mirror used in the experiment was too
short and the higher beams to not illuminate it. Also the glare from the
near source is neglected. - P. G. Sandeman, Assistant Inspector Of Lighting, Edinburgh
- Letter From Holophane, Limited
- The test was not designed to show 75° to advantage. Visibility and
glare was derived from other research, and similar results were gained
from the model street and full sized street in Westminster. A higher beam
would certainly give a higher reflective value but one also gets a
higher glare figure and less visibility. This is the point of our
argument - one wants a bright background, with a minimum of glare and
a maximum of visibility, and we find that the maximum beam at 75°
gives the best compromise of these conflicting factors. Glare from
near sources was not neglected. - E. Stroud, City Engineer, Holophane Limited
- Lighting: Theory
- Bexhill p122
- Brief description of the new installation at Bexhill.
- Lighting: Installations
- An Ingenious Tower-Wagon Outfit For Southport p122
- A new type of Tower Wagon as used by the Gas Department of the
County Borough of Southport is pictured. It is mounted on a 2½-ton
chassis and cane be raised and lowered by hydraulic ram driven from
the engine. All operations can be performed by one man.
- Lighting: Equipment
- Street Lighting Notes p123
- Brief description of the installations at
Castleford, Knutsford, Saltburn and Marske, Broadstairs and St. Peters,
Saltcoats, Lymm, Stoke-under-Ham, New Romney and Greatstoke, Oswaldtwistle,
Jersey, St. Faith's and Aylsham, Ramsey Isle-Of-Wight, Nantwich,
Repton, Salisbury, Hatfield, Norwich, Prestatyn, Ilkeston, Paddington,
Greenwich, Leyton, Stockport, Tauton, Troon and Winchelsea.
- Lighting: Installations
- E.D.A. - E.L.M.A. Street Lighting Conferences p124
- Four street lighting conferences have been held during the autumn. They
were to bring councillors, committee members and officials of many
lighting authorities up-to-date with the progress being made in electric lamps and
electric street lighting practice and the Final Report. The lecture
"The New Era In Electric Lighting" was given followed by "Modern
Street Lighting", a discussion, and then motor coach tours. Events were
held in Hull, Norfolk, London and Manchester
- Other
- Concrete Lamp Columns At Blackpool p124
- H.R.H., the Duke Of Kent, recenty opened two magnificent new
promenades. The long vista of concrete lamp columns is decidely a fine
feature of these new sea walks. They were made by Concrete Utilities.
- Lighting: Installations
- Light On The Roads p124
- A booklet has been issued by the British Commerical Gas Assocation
and deals with many items contained in the Departmental Report issued recently
by the Ministry Of Transport. Some excellent examples of gas street lighting
are included in the booklet including some installations seen recently
in Folkestone.
- Lighting: Publications
- Street Lighting Notes p126, p128
- Brief description of the installations at
Norwich, Leyton, Stockport, Taunton, Troon, Winchelsea, Binbrook, Canterbury,
Derby, Hornsey and the floodlighting of police points in Manchester.
- Lighting: Installations
- Adverts:
British Commercial Gas Association,
William Sugg And Co., Ltd.,
Walter Slingsby and Co., Ltd.,
Siemens Electric Lamps And Supplies Ltd.,
The British Thomson-Houston Co. Ltd.,
Gowshall Ltd.,
Gas Meter Company,
British Sangamo Company Ltd.,
Foster And Pullen Ltd.,
Bromford Tube Co., Ltd.,
Philips Lamps Ltd.,
Radiovisor Parent Ltd.,
REVO Electric Co., Ltd.,
The Horstmann Gear Co., Ltd.,
James Keith And Blackman Co., Ltd.,
British Electrical Development Association, Inc and
The General Electric Co., Ltd.
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