[Music]
[Applause]
we're at one of the UK's leading
firework manufacturers and this is their
125 millimeter Ariel starbursts shell a
20-minute display will launch up to
10,000 fireworks and 60% of them will be
these bad boys each one costs around 30
pounds and contains half a kilo of
explosive enough to launch it to a
height of over 100 meters as you can see
it's much more than a ball of loose
powder and this is how they test the
component parts the basic firework
recipe is flash powder a potent form of
gun powder it's a mixture of potassium
perchlorate and aluminium these
ingredients are mixed together in seven
kilo batches and a small sample is
ignited to make sure it has the
requisite brightness this sample has
been mixed with strontium to make it
glow red and it's clearly a pass
while this sample has barium added to
glow green again it does the trick
nicely if the firework was packed with
this loose powder it would explode in
one instant flash
so the gunpowder mixture is turned into
pellets to prolong the burn time as the
burning pellets fall through the sky
it creates the spreading patterns we're
all familiar with this test checks
whether this particular pellet size will
burn for sufficient time to create the
first diameter of 80 meters there are
two perfectly forming rings of stars a
central ring and an outer ring the outer
ring made of stars of a slightly larger
size therefore they'll be heavier and
when they burst in the middle ignites
these stars and blows them in the circle
formation the inertia of the heavier
larger stars will travel further thus in
the sky you'll see one small ring and
then a larger ring around it
the next test checks the fireworks two
fuses firstly a length of fuses measured
out which will slowly burn inside the
firework to ensure it ignites at the
correct altitude a fuse this length
should burn in about 12 seconds it has
so it's a pass a second external fuse is
needed to launch the firework wrapping
the fuse in paper should contain the hot
gases and make the fuse burn much
quicker I would expect this length of
fuse to burn within a hundredth of a
second looks like a pass to me the final
test is to ensure the firework is no
louder than the European regulation of a
hundred and twenty decibels the same
noise level as a pneumatic drill at
close range
applause