Methods
of Ignition (A Simple, Unpretentious Overview)
Origins
Black
powder is a mixture of saltpeter, sulfur, and charcoal.
This
mixture is mentioned in Chinese texts as early as the 10th century.
The
propulsive force of the gases resulting from the combustion of this powder was
quickly discovered by the learned monk Roger Bacon.
The use
of this powder in a tube came later, as the first "firesticks" did not appear
until the 14th century.
It was in
Europe that the military application of this discovery was most quickly
understood.
However,
numerous technical problems arose.
Launching
a projectile required the combined use of two dangerous components (powder
charge + firing mechanism) whose behavior was unpredictable.
Centuries
passed before the development of a system that no longer posed a danger to the
user.
The First
Weapons
These
were fire sticks, powder darts, or other hand cannons—simple smoothbore tubes
made of wrought iron or cast bronze. Loading was done through the muzzle, where
powder was poured in, followed by the projectile. Wadding was then inserted to
protect the charge.
The
charge was ignited through a hole, the "touch," in the breech, into which fine
priming powder was placed.
The
effectiveness of this system must have been quite unreliable and not without
danger (proximity of an open flame near the powder reservoir, spitting from the
touch hole, humidity, rain, wind, etc.).
Locks
In the
15th century, the first prototypes of coil locks appeared.
The
touchhole was pierced on the right, fitted with a cover and a pan to hold the
priming powder. The coil was a pivoting, S-shaped metal piece that could receive
a match and, when lit, be tilted onto the pan and the powder.
Later,
the system was improved by the addition of a trigger mechanism.
In the
last quarter of the 16th century, the wheel lock appeared. This significantly
more complex system could be compared to a clockwork mechanism. A washer was
connected to a spring that was wound using a key. The hammer was fitted with a
piece of pyrite or flint.
Pulling
the trigger released the hammer, which struck the pan. The vigorous friction of
the pyrite against the steel created a spark that ignited the powder.
This
system had the advantage of being transportable with a cocked weapon and belt,
and of being immediately usable without the serious risk of a lit match.
The 16th
century also saw the birth of the flintlock mechanism, which came in several
variations, the most popular being the French-style lock. The hammer held a
beveled flint in its jaws, the wheel was absent, and the pan was covered by a
right-angled piece, the lower part of which covered the pan. The upper part
served as the frizzen.
The
hammer, released by the trigger pull, fell onto the frizzen, causing it to tip
over and exposing the pan.
The
resulting spark ignited the powder.
Although
more sophisticated, this system was often prone to fouling of the touchhole and
barrel. The flints chipped quickly and often had to be replaced.
Despite
this, one misfire in fifteen shots was possible!
The 18th
century was the century of chemistry and physics, notably with the discovery of
mercury and silver fulminates (BERTHOLET & HOWARD).
However,
it was FORSYTH who had the idea of modifying the flintlock mechanism and
replacing the powder with fulminate powder contained in a magazine commonly
referred to as a "perfume bottle." The flintlock hammer was replaced by a
hammer.
The
impact of this hammer on a piston was enough to trigger the explosion.
The
19th-century revolution was breech-loading. In 1828, Casimir Lefaucheux invented
the first break-action shotgun with a T-lock, followed in 1836 by the invention
of the pinfire or vertical percussion cartridge, which remained in use until the
beginning of the 20th century. The gunsmith LORON of Versailles (but originally
from Liège) invented the centerfire break-action shotgun without external
hammers (hammerless).
Meanwhile, Flobert had invented the famous rimfire cartridge, which is still
used today in small-caliber firearms.
GG †