How would you explain this sentence?
The Painter keeps assistant boys running as late as the last trolley runs. Sometimes you mix, or tie ropes, or carry things up the scaffolds. The Palacio has spiked iron lanterns hanging from the ceiling, you have to watch your head or could crown yourself. The stairwell mural is the size of two walls, one above the other. It is meant to be finished before the end of the year.
How would you explain the first sentence: The Painter keeps assistant boys running as late as the last trolley runs?