Sense Sonnet - Pumper

Nilometer

In ancient Egypt, a sure bet
Was that the Nile River would flood.
The vital question was how wet
Would be the flood plain turned to mud?
Thus, the nilometer was built,
For predicting whether or not
The flood was good with new rich silt,
Or bad with famine or worse brought.
A vertical tower submerged
Down into waters of the Nile.
High priests and royals then converged,
And water depth marks did compile.

The better the predictions made,
The more crop taxes would be paid.