“Good night,” said Adam. She did not answer him. At the top
of the first flight he looked back. Her head was raised, and now her
chin made a shadow on her throat and her eyes had no pupils. His
room smelled of dust dampened and dried many times. He picked a match
from his block and scratched it on the side of the block. He lighted
the shank of candle in the japanned candlestick and regarded the
bed-as spineless as a hammock and covered with a dirty patchwork
quilt, the cotton batting spilling from the edges. The porch
steps complained again, and Adam knew the woman would be standing in
her doorway ready to spray inhospitality on the new arrival. Adam
sat down in a straight chair and put his elbows on his knees and
supported his chin in his hands. A roomer down the hall began a
patient, continuing cough against the quiet night. (John
Steinbeck, East of Eden)
Does the highlighted part mean this boarding house has rooms in the first floor as well as the second; and the roomer is in a room in the first floor? What does the ‘down’ mean?
Look at the definition of "down" as a preposition here. "He is walking down the street" will mean "He is walking along the street". "He lives down the hall" will mean "He lives on the same floor, along the hallway, a few doors away."