The author has studied in a previous paper [Pac. J. Math. 124, 375-402 (1986)] a flow on the space of measured foliations on a surface. This flow on \({\mathcal M}{\mathcal F}\) is an analogue of the classical Fenchel- Nielsen flow on the Teichmüller space and associated to a nontrivial circle on the surface in question. In the paper the author proves that a suitable reparametrization of the Fenchel-Nielsen flow extends to the Thurston boundary \({\mathcal P}{\mathcal M}{\mathcal F}\) of the Teichmüller space and that this extension is equal to the quotient of the flow on \({\mathcal M}{\mathcal F}\) (recall that \({\mathcal P}{\mathcal M}{\mathcal F}={\mathcal M}{\mathcal F}\setminus 0/{\mathbb{R}}_+)\). This result was inspired by an (unpublished) theorem due to S. P. Kerchkoff. According to this theorem the Fenchel- Nielsen flow itself extends to the identity on \({\mathcal P}{\mathcal M}{\mathcal F}\).