Labor not unwillingly

 Labor not unwillingly, nor without regard to the common interest, nor without due consideration, nor with distraction, nor let studied ornament set off thy thoughts, and be not either a man of many words, or busy about too many things.  Marcus Aurelius.  Meditations.  Book 3.

Image: Relief from the tomb of the Haterii, a family of builders who constructed their mausoleum along the ancient via Labicana in the early years of the 2nd century CE courtesy of the Vatican Museums. It depicts a Roman polyspaston crane that, when worked by four men at both sides of the winch, could lift 3000 kg. If the winch was replaced by a treadwheel, the maximum load could be doubled to 6000 kg at only half the crew, since the treadwheel possesses a much bigger mechanical advantage due to its larger diameter. This meant that, in comparison to the construction of the ancient Egyptian pyramids, where about 50 men were needed to move a 2.5 ton stone block up the ramp (50 kg per person), the lifting capability of the Roman Polyspaston proved to be 60 times more efficient (3000 kg per person).