What question is Helen Keller answering in her letter?

Which word best describes the tone of this excerpt from daly's sixteen

When i was four years old, my dad and i a tree in our front yard. it was a tiny, fragile sapling. he promised me that it would grow tall and strong, but he said that i had to be patient. until i turned 18 years old, dad and i it every year on my birthday. choose the words that correctly fill in the blanks.

What is meant by “eternally burning black pipes”? what is this implying about the personality of the firemen?