to misdevote one's energies to a thankless task

This first electric railway under London has thus now become an integral part of the ramified tube system of the Metropolis.

We have all sorts of evidence which incriminates you.

So it is with great regret, after long soul-searching, that I must inform you that I cannot in good conscience support your decision to pardon former President [Richard] Nixon even before he has been charged with the commission of any crime.