Lloyd E. Sponenburgh wrote:
"Lloyd E. Sponenburgh" wrote in message
...

The stacks did become slack during extreme heat. The brass monkey became
looser. Only when it tightened excessively did the balls begin to roll
off.

Keep in mind that a triangular pyramid stack of spheres is stable to +-60
degrees of roll. That's a heavy sea.



From the rather small niche of black powder historians, the story comes this
way:

Anyone who physically handled cannon balls or powder was known as a "ball
monkey" or "powder monkey". The term "powder monkey" is still used today.
"Ball monkey" seems to have been lost.

On board most armed ships of the British fleet were triangular brass racks -
low bars of brass forged into an equilateral triangle - mounted to the
decks, into which to stack cannon balls in the familiar pyramid fashion.
This, to ready the balls for quick access.

Although the "brass monkeys" were only an inch or two high, the stacks made
within them were quite stable -- until the temperature dropped very, very
cold. At that point, due to different coefficients of expansion between
brass and iron, the balls came tumbling off their racks.

Thus, "cold enough to freeze the balls off a brass monkey". Of course, the
vulgar connotations came quite soon after. G

LLoyd





LLoyd,

The thermal coeficients of expansion a

Brass: 11*10^-6 in/in/deg F

Iron: 7*10^-6 in/in/deg F

The differential is 4*10^-6 in/in/deg F

Thus, a pile of cannonballs and a rack say 4 feet on a side dropping in
temperature from say 70 F to -20 F would have an overall differential
length change of

4 * 12 * 4e-6 * 90 = 0.017"

Now LLoyd, please tell the group what you think that rack must have
looked like, and just how seventeen thou of change in a four foot long
dimension made the balls fall off it.

I have learned that the only person who is a bigger fool than one who is
wrong and can't see it.....is that person who continues to debate him.

So, I hereby declare you correct and resign from any further discussion
of cannonballs and brass racks with you.

Relish your victory, LLoyd.

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."