The first image of the corona in Fe XI 7892 A was taken during the total solar eclipse of 29 March 2006. It revealed a number of surprises, primarily an emission extending out to at least 3 Rs and localized regions of enhanced Fe10+ ion density relative to electrons. Subsequent observations of this spectral line were successfully made during the eclipses of 2008 and 2009. These Fe XI observations will be presented, together with simultaneous measurements of the more widely observed Fe X 6374, Fe XIII 10747 and Fe XIV 5303 A lines. Particular emphasis will be placed on the new insights into the thermodynamic properties of the inner corona gained by this suite of measurements.