The MTA again. The word “baseline” got me wondering, and there’s a good chance that this marker is on the centerline of the IRT line as it heads southeast from the Bowling Green station to the Joralemon tunnel to Brooklyn.

The MTA again. The word “baseline” got me wondering, and there’s a good chance that this marker is on the centerline of the IRT line as it heads southeast from the Bowling Green station to the Joralemon tunnel to Brooklyn.