（解説文要約）
明治中期の炭坑は7、8歳の子どもでも坑内に下がっていました。
石炭は通常、家族、あるいは他人でも大人二人一組で、一日2トン半くらい掘っていました。
この作品には、子どもたちが、石炭をスラから炭車に積みかえる場面が描かれています。
やはり子どもなので、幼い兄弟二人合わせて一人前です。
Around 1900, there were children as young as 7 or 8 years old, going down into the pits to help with the family earnings.
Coal miners often worked in a pair of adults, typically family members, but not exclusively.
These teams mined approximately 2 and a half tons of coal a day.
This is a picture of a young brother and sister working as a team, transferring coal from a Sura to a skip.
Because they are still children, they are considered only one of the adult pair.