The M. & S. Traction Company, according to a newspaper search, operated in central New Jersey--M. & S. standing for Middlesex and Somerset, two New Jersey counties. Therefore, Frank Lees' information -- "Summer trolley car on Baltimore Avenue, on line from Media to Glen Riddle" -- is likely wrong.
Probably at C. Frank Williamson’s lumber yard, near railroad station in Media. Scene includes railroad flatbed cars loaded with lumber, woodsmen with axes, and huge uncut tree trunks with bark still attached.