The poem "Icarus Again" opens during what seems like a school science experiment on flight. The recognition of the mythology character Icarus is needed.
Icarus, needing to escape from Crete, uses wings his craftsman father, Daedalus, created for him. Daedalus warns Icarus not to fly to close to the sun for the fact the sun will burn the feathers and melt the wax from which the wings were constructed.
Icarus, ignoring the warnings of his father, decides that he loves the feeling of flying and soars close to the sun. Just as his father warned, the wax on the wings melts and Icarus plummets to his death.
As for the reference to Icarus in Devenish's poem, the mythological man is referenced as being reanimated in the structures created by the children. Much like the man Icarus, the creations are seen "exploding over and over again."
In the end, the speaker feels sorry for the children. With happiness in their hearts they had thrown their creations off of the cliff only to watch them crash to the earth. The "pure Icarian sky suddenly emptied of their child." Love and faith is simply not enough: constantly "the light heart [is] pulling us down."