Rosalind, I agree. The piece is lyrical, with the melody line in right hand needing to be brought out. Sometimes there are ornaments such as two-handed trills near a cadence, with no ritardando indicated. To try to keep up with a metronome at the marked speed takes away from the enjoyment of the composition for both harpist and audience, in my opinion. I would suggest a maximum of 116 per quarter beat, and students could start even slower. Then in the various sections allow some rubato to let the piece breathe a bit; otherwise it might sound too mechanical, especially as the main theme keeps recurring.