（解説文要約）
坑内では、効率よく炭車を動かすことがとても重要でした。
炭車が回ってこないと、掘り出した石炭を置く場所がなくなり、作業が止まってしまうからです。
後山が、大急ぎで炭車に石炭を積み込んでいる様子が描かれています。
この作業にも上手い下手があったそうです。
In the pit, efficient operation of coal cars was essential.
If the coal car was not sent on time, mining had to stop because there was no space to stock the coal that had been dug out.
This painting shows a carrier, called "Atoyama", loading coal into a coal car in a hurry.
Her speed relied on her technique and experience.