163)The
“25 Euro Silver-Niobium Coin Series”: (Part vi): 2003 onwards minted by the
Austrian Mint by using Niobium and Niobium metal insertion technology for the
first time anywhere in the World of Numismatics: The Sixth coin in the Series: “Fascinating
light” (2008):
Baron
Karl Auer von Welsbach or Carl Auer, Freiherr von Welsbach (01.09.1858 – 04.08.1929):
Baron Karl Auer von
Welsbach was an Austrian chemist and engineer who invented the gas mantle,
which led to a greatly increased output of light by using Gas lamps. He was a
brilliant chemist who was born in Vienna in 1858. He was a key figure in the
development of gas lighting. The technology developed by Carl Auer van Welsbach
is still in use in billions of light bulbs around the world today.
In 1885, he
discovered and isolated the elements Praseodymium (green) and Neodymium (pink)
– both Lanthanides bearing the atomic numbers 59 and 60 respectively on the
Periodic Table of Elements, from a mixture called Didymium which was hitherto itself
considered to be an element.
His interest in rare-earth
elements led him to further discover that a fabric impregnated with a
mixture of thorium nitrate and cerium nitrate could be made into a mantle that
glowed brightly when heated by a gas flame. He patented the procedure and the
resultant Welsbach gas mantle which he called “Auerlicht” and which was, in turn, developed by using a
chemical mixture of 60% magnesium oxide, 20% yttrium oxide, which he called “Actinophor”, vastly improved gas
lighting. To produce a mantle, guncotton is impregnated with a mixture of “Actinophor” and then heated, the cotton
eventually burns away leaving a solid, though fragile, ash which glows brightly
when heated.
These original mantles gave
off a green-tinted light but were not very successful. In 1889, Welsbach’s
first Company formed to sell these mantles wound up due to the failure of these
mantles to become popular.
Not to be discouraged, in
1890, he introduced a new form of mantle based on a mixture of 99% thorium
dioxide and 1% Cerium (IV) oxide. This
mantle proved to be more robust and gave off a much whiter light.
He
successfully converted his advanced discovery into a commercially successful
product and by 1891, his mantles were selling all over Europe.
He then researched on the
development of metal-filament mantles, first with platinum wiring and then with
Osmium. He developed a new method which mixed Osmium oxide powder with rubber
or sugar into a paste, which was then squeezed through a nozzle and fired. The
paste burnt away, leaving a fine wire of Osmium.
This
was being positioned by him as the new mantle, but during this time electricity
was introduced, therefore, Welsbach began to research methods to use the
filaments as a replacement for the electric arc light.
In 1898, he
succeeded in producing a metal filament light bulb which was a huge improvement
on the existing carbon filaments of the day and lasted much longer by using
about half the electricity for the same amount of light. Welsbach, thus,
introduced the first metallic filament for incandescent lamps. Although the
Osmium (atomic numbers 76 on the Periodic Table of Elements) that he used was
considered to be too rare for general use, Welsbach’s improvements led to the
development of the tungsten filament and the modern light bulb.
Today, although the
incandescent lamp/bulb has greatly supplanted gas lighting, nevertheless, the
gas mantle is still used widely in kerosene and other lanterns etc.
Welsbach
is particularly well known for the development of Misch metal, a mixture of
Cerium and other rare earth elements, which he combined with iron to make
Auer’s metal, the first improvement over flint and steel for making sparks
since ancient times.
In 1903, he
registered another patent for a “fire striker” (Flint), having a composition
named Ferrocerium, consisting of Pyrophoric alloys, i.e. 70% Cerium and 30%
Iron which when scratched or struck would give off sparks. His advancement of
the flint was used in modern cigarette lighters and, also, in strikers for
lighting gas jets for the gas mantles which brought light to the streets of
Europe in the late 19th century and led to the development of the
filament light bulb. This system has remained in wide use in gas/petrol
lighters today.
In 1907, he
registered a company “Treibacher
Chemische Werke GesmbH” to build and market this device.
For the rest of his life,
he continued to publish a number of papers on chemical separation and
spectroscopy which inspired several scientists to explore chemistry related
solutions in various fields.
In 1922, he
presented a major paper on his work on the separation of Radioactive elements.
The
Silver-Niobium coin titled “Fascinating Light”:
This
coin issued in 2008, also commemorates the 150th Birth Anniversary
of Carl Auer van Welsbach together with
one of the earliest recognised energy sources – light.
The Obverse of this coin shows a streetlight keeper involved in
the maintenance/lighting up of a gas lamp/lantern outside Vienna’s neo-gothic
city hall. He is shown as using a step-ladder which gives an impression of the
considerable height at which the gas lantern is placed. The ladder and one foot of the light-keeper as
well as a portion of the pillar on which the lamp is placed spills over from
the Niobium core onto the outer silver ring of the coin. These lamps were in use
since 1800s in Vienna.
On the upper periphery of
the coin is mentioned the name of the country “Republik Osterreich” (meaning the “Republic of Austria”). On the
lower periphery is mentioned the denomination of the coin “25 Euro” and the
year of issue “2008”.
The Reverse of the coin is depicted the glowing Sun as the
ultimate source of light, placed in the middle of this face of the coin and
artificial light lamps placed in a manner which shows the evolution of lighting
technology – several methods of illumination from the gas light to incandescent
light bulbs and neon lamps to modern Light Emitting Diodes (LEDs),
with the engravings spilling into the outer silver ring. This face also depicts
a partial portrait of Welsbach on the left hand side.
The
Niobium core on this coin has a green colour. This colour has
been achieved by heat treating and oxidising the niobium core and applying an
extra finish prior to its striking.
The
specifications of the coin are:
Face value: 25 Euros;
Metallic composition: Outer ring: Silver (Ag) 900 – 9 gms, Niobium 998 – 6.50 gms;
Diameter: 34 mm; Weight: 16.50 gms; Edge: smooth.
Incandescent
light bulb/lamp: This is an electric light produced with a
wire filament heated to a high temperature by an electric current passing
through it, until it glows – incandescence. The hot filament is protected from
oxidation with a glass or quartz bulb that is filled with inert gas or
evacuated. In a halogen lamp, filament evaporation is prevented by a chemical
process that redeposits metal vapour onto the filament, extending its life. The
light bulb is supplied with electrical current by feed-through terminals or
wires embedded in the glass. Most bulbs are used in a socket which provides
mechanical support and electrical connections. Incandescent bulbs are
manufactured in a wide range of sizes, light output and voltage ratings say
from 1.5 volts to about 300 volts and are used as table lamps, car headlamps,
flashlights, in households, decorative and advertising lighting etc.
Incandescent bulbs are much less efficient than most other types of electric
lighting. They convert less than 5% of the energy they use into visible light
while the remaining energy is converted into heat.
Neon
Lamp: A neon lamp is a miniature gas discharge lamp which
consists of a small glass capsule that contains a mixture of Neon and other
gases at a low pressure and two electrodes (an anode and a cathode). When
sufficient voltage is applied and sufficient current is supplied between the
electrodes, the lamp produces an orange glow discharge. The glowing portion in
the lamp is a thin region near the cathode. The larger and much longer neon
signs are also glow discharges, but they use the positive column which is not
present in the ordinary neon lamp. Neon glow lamps are widely used as indicator
lamps in the displays of electronic instruments, appliances, advertisement
hoardings etc.
Light
Emitting Diodes (LED): this is a two-lead semiconductor
light source. It is a basic pn-junction diode (this is a boundary or interface
between two types of semi-conductor material, p-type and n-type, inside a
single crystal of semi-conductor) which emits light when activated. When a
voltage is applied to the leads, electrons recombine with electron holes within
the device, releasing energy in the form of photons creating an effect called
“electroluminescence” and the colour of the light (corresponding to the energy
of the photon) is determined by the energy band gap (this is an energy range in
a solid where no electron states can exist) of the semi-conductor.
The following coins have
been issued in this Series:
2003 – 700 years old city
hall in Tyrol or Tirol.
2004 – 150 years Semmering
Alpine Railway
2005 – 50 years of
Television
2006 – The European
Satellite Navigation
2007 – Austrian Aviators
2008 – Fascinating light
2009 – Year of astronomy
2010 – Renewable Energy
Sources.
2011 – Robotics
2012 – Bionics
2013 – Drilling tunnels
2014 - Evolution
2015 - Cosmology
Links:
1) The 25 Euro Silver-Niobium Coin Series issued by the Austrian Mint: First Coin: "700 Years of Hall City in Tirol or Tyrol"
For posts on COTY (Coin of the Year) winners since 2015 in a competition held by Krause Publications of Germany, please visit the following links:
2015 - Cosmology
Links:
1) The 25 Euro Silver-Niobium Coin Series issued by the Austrian Mint: First Coin: "700 Years of Hall City in Tirol or Tyrol"
Links to posts on Federal Republic of Germany issues and other posts on this blog:
For posts on COTY (Coin of the Year) winners since 2015 in a competition held by Krause Publications of Germany, please visit the following links:
Anand Varma has commented:
ReplyDelete"Kings and their kingdoms do not remain forever, but an invention of a scientist is an everlasting gift to mankind . Nice history of this great coin . Keep it up . Good study!!"
Thank you so much, Anand. Much appreciate your encouragement. Your observation has a deep philosophical meaning, indeed!
DeleteKrishna Tope has commented:
ReplyDelete"One of best coin information blog . Great job sir".
Thank you so much for your encouraging comment, Krishna.
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