[jacquesm]

Maybe all that happened is that they tried picking up their work after some rain had fallen (this does happen, even there) and they found the work to go much easier. Then when it dried up again they found it got harder, so they re-created the conditions artificially.

[junto]

I imagine many discoveries are made in this manner. I.e. accidental. Sometimes it can take centuries though for someone to see something obvious and realise its potential.