"Sunset Island" is a long, sustained description of the setting sun, and the astronomy of this. The music, especially the middle section, portrays the vastness of space, and the movement of the celestial spheres. I borrowed from my earlier work, the 'Songs of Time'. The 7th movement is a setting of the opening lines of a poem by Henry Vaughan [1621-1695] called 'The World', which describes the movement of the planets around the Sun. I know that Vaughan would not have seen an 'orrery' - a mechanical model of the solar system demonstrating the relative movement of the planets & moons round the sun, according to the heliocentric model - since the first such device was not made until nine years after his death , in 1704, by watchmakers George Graham & Thomas Tompion, for Charles Boyle, 4th Earl of Orrery. However he would have known of the teachings of, amongst others, Nicolaus Copernicus, who published the a description of the heliocentric universe such as had been proposed by some of the Greek philosophers. Kepler and Newton too were contemporaries of Vaughan.
For me, 'Sunset Island' is my family's affectionate name for the North Bishop, behind which, for a while each Summer, the sun sets as from our viewpoint in our house above Porth Sele, a bungalow built in the mid '30s by my Great Aunt Heather, in which I have spent years of my entire lifetime.
I Saw Eternity the other night, Like a great ring of pure and endless light, All calm, as it was bright; And round about it, Time in hours, days, years, Driv'n by the spheres Like a vast shadow mov'd; in which the world And all her train were hurl'd.