another text that bears on these matters is the prose preface to kortirion among the trees ( 1915 ) , which has been given in part i 25 -- 6 , but which i repeat here : ( 9 ) now on a time the fairies dwelt in the lonely isle after the great wars with melko and the ruin of gondolin ; and they builded a fair city amidmost of that island , and it was girt with trees .