Thore­au, Emer­son, and Hawthorne all record in their jour­nals a moment when the shrill whis­tle of the Fitch­burg Rail­road intrud­ed upon the tran­quil­i­ty of the Con­cord woods. The track of that rail­road passed very close to Walden Pond, and Thore­au espe­cial­ly took note of the way the smoke-belch­ing loco­mo­tive dis­rupt­ed his coun­try reveries.