Minus One

A carpenter named Charlie Bratticks
Who had a taste for mathematics
One summer Tuesday, just for fun
Made a wooden cube side minus one

Though this to you may seem wrong
He made it minus one foot long
Which meant (I hope your brains aren't frothing)
Its length was one foot less than nothing

Its width the same (you're not asleep?)
And likewise minus one foot deep
Giving, when multiplied (be solemn)
Minus one cubic foot of volume

With sweating brow this cube he sawed
Through areas of solid board
For though each cut had minus length
Minus times minus sapped his strength

A second cube he made, but thus
This time each one foot length was plus
Meaning of course that here one put
For volume, plus one cubic foot

So now he had, just for his sins
Two cubes as like as deviant twins
And feeling one should know the worst
He placed the second in the first

One plus, one minus - there's no doubt
The edges simply cancelled out
So did the volume, nothing gained
Only the surfaces remained

Well may you open wide your eyes
For those were now of double size
On something now, thanks to his skill
Took up no room and measured nil

From solid ebony he'd cut
These bulky objects, but
All that remained was now a thin
Black sharply angled sort of skin

Of twelve square feet - which though not small
Weighed nothing, filled no space at all
It stands there yet on Charlies floor
He can't think what to use it for