In answer to the inquiry respecting this singular man, I beg to say that I remember him between the years 1826 and 1830, as a shoemaker in Norwich. He was in a low rank of trade, and in poor circumstances, which he endeavoured to improve by exhibiting at private houses an orrery of his own making. He was recognised as a "genius;" but, as may be seen by his writings, had little reverence for established forms of belief. At the period of which I speak, which was soon after the publication of his first work, I knew but little of his mind, and lost sight of him altogether till about 1840. Then circumstances connected with my own line of study led me to call on him in Doughty's Hospital, Norwich, an asylum for aged persons. I found him surrounded by astronomical apparatus, books, the tools of his former trade, and all kinds of strange litters. In the conversation that ensued, I learned much of the workings of his mind; though his high self-appreciation could not descend to unreserved converse with a woman. My object was, to ascertain by what steps he had arrived at his theory of the earth's motion, but I could gain nothing distinct. He mentioned the _Asiatic Researches_ as containing vast information on his peculiar subject; quoted Latin, and I think Greek, authors; and seemed to place great dependence on Maurice and Bryant; but, above all, on Capt. Wilford's _Essays_. He showed me some elaborate calculations, at which he was then working and still fancied himself qualified, perhaps destined, to head a great revolution in the astronomical world. I cannot say how far his knowledge of geology went, as I am not well acquainted with that science. He had evidently read and studied deeply, but alone; his own intellect had never been brushed by the intellects and superior information of truly scientific men, and it appeared to me that a vast deal of dirt, real dirt, had accumulated in his mind. My visit disappointed and pained me, but he seemed gratified, and I therefore promised to call again, which I did, but he was not at home. I think this visit was soon after he had removed into the hospital, for I then purchased his last work, _The Age of Mental Emancipation_, published 1836, before he obtained that asylum. He died before 1849, but I do not know the exact year. In any next visit to Norwich, I will make inquiries on all points relating to Mackey, of the very few persons now left who took interest in him, and I think I can find the printer of his last pamphlet. I have not the work mentioned in "N. & Q.;" but, besides his last work, I have _The Mythological Astronomy of the Ancients demonstrated_, which is partly in poetry.