Since 1874, an authentic, steam-powered locomotive has traversed the countryside of the Isle of Man, between the coastal village of Port Erin and the capital of Douglas, huffing and puffing through idyllic green pastures, rolling hills, grazing sheep, and coastal cliffs overlooking the Irish Sea. Several times per day, these old engines chug along, blowing hoarse, reedy whistles at every crossing. With brief stops in several towns and hamlets, including Castletown, the Isle of Man’s former capital and home to its parliament building, The Old House of Keys, a one-way…