The extreme belching of smoke from a long, gray exhaust pipe filled the air, floating east with the breeze, as the loud clanking of the great engine beat with rhythmic precision. A crowd inevitably gathered as owner D.W. Ruhter of Moab, Utah, started the rare engine; rare in this case meaning singular, as this is the only Stover 20 HP crude oil engine, complete and working, known to exist.