Productivity is being able to do things that you were never able to do before.

The light was fading, and with it, the warmth of the day.

The chief beauty about time is that you cannot waste it in advance. The next year, the next day, the next hour are lying ready for you, as perfect, as unspoiled, as if you had never wasted or misapplied a single moment in all your life. You can turn over a new leaf every hour if you choose.

The future of coal lies not in its quantity but in how cleanly and efficiently we can use it.