[Sidenote: _Enduring Power of Mind_]

"Don't be horrified when I tell you that for the whole of the actual
siege, and in truth for some little time before, I almost lived on
brandy. Appetite for food I had none, but I forced myself to eat just
sufficient to sustain life, and I had an incessant craving for brandy,
as the strongest stimulant I could get. Strange to say, I was quite
unconscious of its affecting me in the slightest degree.

"_The excitement of the work was so great that no lesser one seemed to
have any chance against it, and I certainly never found my intellect
clearer or my nerves stronger in my life._"

Such is the profound resourcefulness and enduring power of the human
mind.




CHAPTER II

RESERVES OF POWER


[Sidenote: _Man's Potential and Kinetic Energies_]

Stored-up energy not in use has been given a name by scientific men.
They call it _potential energy_. In this way it is distinguished from
_kinetic_ or circulating energy by which is meant energy that is at