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� AMAZIG ANSWERS TO CURIOUS QUESTIONS ------------------

How do dynamo What were the
generators work? What was the first antiseptics?

dynamo electric generator converts Leyden Jar? T he theory that germs, in
A mechanical energy into electrical energy. the form of microscopic
It rotates coils of metal wire (the mechanical T he Leyden Jar was independently organisms, are responsible
energy) within a magnetic field to force the invented by the Dutch physicist for infection encouraged
field to push on the electrons in the metal and Pieter van Musschenbroek and Ewald the use of antiseptics in
vary its flux (amount of field passing through Georg von Kleist, Dean of the Kamin conjunction with better
the coils). This, as according to Faraday's law Cathedral in Pomeranian, in 1745. standards of hygiene.
- the induced electromotive force in any Musschenbroek, based at the The widespread use of
closed circuit is equal to the time rate of University of Leiden (Leyden), kept antiseptics in hospitals was
change of the magnetic flux through the better records and it became known heralded by the work of
circuit - causes the induction of electric as the Leyden Jar. British surgeon Joseph Lister,
current (electrical energy). The Leyden Jar enables you to who was the professor of surgery at
Therefore, dynamos have three main store static electricity for several the University of Glasgow in the late 1860s.
components - the stator, armature and minutes or even days. To discharge it He was inspired by French chemist Louis
commutator. The stator is a stationary you merely complete the circuit Pasteur, who claimed that gangrene is
structural frame that provides the dynamo's between the outer foil and the top of caused by micro-organisms that can be
constant magnetic field, while the armature is the rod. If, for example, you touch killed off by heat, filtration or the application
the dynamo's central set of wire windings that them you will receive a very of chemicals.
are rotated by mechanical energy. The powerful electric shock that can Lister experimented with various forms of
commutator is a rotary electric switch that is cause serious injury. chemical antiseptic. He discovered that a
mounted to the armature's central shaft and In the 19th Century they were used solution of carbolic acid (phenol) applied to
reverses the electrical potential within the wire to experiment with electricity and dressings, wounds and his surgical
with each half turn of the armature, to convert promoted as 'cure all' devices. These instruments greatly improved recovery from
alternating current into direct current. were the first capacitors, and the surgical procedures.
Today, direct current dynamos are rarely same principles are used for Phenol kills germs by disrupting their cell
used, due to the worldwide dominance of capacitors used today in amplifiers walls, which causes their cellular contents to
alternating current and its ease of conversion and radio equipment. leak out. If the solution is too strong it can also
using solid-state materials. be damaging to skin. German bacteriologist
Heinrich Koch proved that tuberculosis was
caused by bacterium in 1882. This helped
What's inside a naval mine? bring about the acceptance of antiseptic
procedures throughout the world.

aval mines are a contact-initiated type substance will cause direct damage - ie a
Nof explosive that can either be moored hole in the hull will be blown open. This will
to the ocean floor by steel cables or left free cause severe damage to multiple watertight
to drift around unimpeded. Modern contact compartments and expose nearby crew to How did early
mines work by encasing a large quantity of an severe shrapnel debris. If the vessel is of
explosive substance - such as small dimensions, an explosion of this type music boxes work?
trinitrotoluene (TNT) - in a will likely sink it; if of large
spherical metal shell covered dimensions, it will cause it to T he music or musical box consists
with hollow lead become immobile. Second, of a cylinder that is rotated by a small
protuberances, each when the mine explodes it will clockwork mechanism.
containing a glass vial filled cause a bubble within the Pins placed on the cylinder pluck the teeth
with sulphuric acid. When water, which - due to the of a stationary steel comb to create a tune (or
crushed by the hull of a ship difference in localised 'air' as it is sometimes called). The movement
or submarine, these pressure - will collapse from works best in a wooden box as it acts as an
protuberances, known as Hertz the bottom. If this collapse ideal medium for transmitting and amplifying
Horns, cause the vial inside to occurs onto the ship's hull its the sound.
break and the acid to run down into force can puncture a metre-wide Music boxes quickly came into vogue in the
a lead-acid battery stripped of acid hole straight through the ship, killing all 19th Century when they were first made by
electrolyte. The mixing of the freed acid with crew in its path instantly. Finally, contact watchmakers in Switzerland. These devices
the battery energises it, triggering the mine explosions produce a shock wave that could become quite elaborate and employed
electronic detonator, causing the mine's can cause any nearby vessel to resonate multiple cylinders or discs to play complex
substance to ignite and explode. violently, causing engines to rip from their tunes. Today, they are still popular as
Damage rendered to vessels by contact housing cases of large ships and breaking jewellery boxes and as novelties, and can be
mines is three-fold. First, the explosive smaller ones apart entirely. highly sought after by collectors.

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