On the power of percussion
Why many small blows cannot equal one, and why force spread over time fails.
Leonardo reflects on the power of percussion: many small blows will drive a nail into wood, and if those blows could be gathered into one they would have far greater power than they hold separately. Yet the same percussive power, once divided into small particles and applied slowly over a long time on the nail, could never gain any degree of penetration. Force, he implies, must be delivered at once to be effective.
On this page
United blows exceed their scattered sum
Many small blows will sink a nail into wood, but joined into a single blow they would have much greater power than they possess separately in their particles. The gathering of force multiplies its effect.
Force spread slowly over time gains no entry
If a percussive power sufficient to drive a nail home is divided into many particles and applied slowly over a long time upon the nail, it could never win any degree of penetration into the wood. The same total force, drawn out, accomplishes nothing.