During the period of his diplomatic service he added almost nothing to his permanent literary product. In 1869 he had published _Under the Willows_, a collection that contains some of his finest poems. In the same year _The Cathedral_ was published, a stately poem in blank verse, profound in thought, with many passages of great poetic beauty. In 1888 a final collection of poems was published, entitled _Heartsease and Rue_, which opened with the memorial poem, _Agassiz_, an elegy that would not be too highly honored by being bound in a golden volume with _Lycidas_, _Adonais_ and _Thyrsis_. Going back to his earliest literary studies, he again (1887) lectured at the Lowell Institute on the old dramatists, Occasionally he gave a poem to the magazines and a collection of these _Last Poems_ was made in 1895 by Professor Norton. During these years were written many of the charming _Letters_ to personal friends, which rank with the finest literary letters ever printed and must always be regarded as an important part of his prose works. It was a gracious boon of providence that Lowell was permitted to spend his last years at Elmwood, with his daughter, Mrs. Burnett, and his grandchildren. There again, as in the early days, he watched the orioles building their nests and listened to the tricksy catbird's call. To an English friend he writes: "I watch the moon rise behind the same trees through which I first saw it seventy years ago and have a strange feeling of permanence, as if I should watch it seventy years longer." In the old library by the familiar fireplace he sat, when the shadows were playing among his beloved books, communing with the beautiful past. What unwritten poems of pathos and sweetness may have ministered to his great soul we cannot know. In 1890 a fatal disease came upon him, and after long and heroic endurance of pain he died, August 12, 1891, and under the trees of Mt. Auburn he rests, as in life still near his great neighbor Longfellow. In a memorial poem Oliver Wendell Holmes spoke for the thousands who mourned: "Peace to thy slumber in the forest shade, Poet and patriot, every gift was thine; Thy name shall live while summers bloom and fade And grateful memory guard thy leafy shrine."