It is interesting to find that old mysteries can be solved through research ... even when different solutions emerge. For instance, a writer in American Gardening 19: 392 (May 21, 1898) got his information about Rev. Harison from the old man's granddaughter. She seems not to have been aware that old George was a bachelor, according to Wright.

Leonard Barron (1901) weighed in by warning against the double r, then compensating by doubling the s. He
acknowledged the granddaughter while rejecting the "Rev.". Along with the others, he repeated the error that 'Hogg's Yellow' was a synonym for 'Harison's Yellow.' In fact, 'Hogg's Yellow' and 'Hogg's Straw-colored' were seedlings from 'Harison's Yellow'. Hovey (1845) listed these three together, as well as 'Persian Yellow' and 'Williams' Double Yellow'.

C. M. Hovey (1883) wrote of his travels in search of Camellias, "About 1830."
"Returning home, on my way I accidentally became acquainted with the late Mr. P. Dunlap, then gardener close to New York. He, too, had some fine seedlings, and he introduced me to an old sailor and neighbour, Capt. Harrison, who had a most beautiful double white, more exquisite than alba plena, a perfect gem to-day. This same Capt. Harrison also raised the yellow Harrison's Rose, which I believe some English rosarians consider to be about the most beautiful and valuable hardy or yellow Rose extant. So you see we do raise some good things in America, or, perhaps I should say, did so fifty years ago."

I cannot locate a "P. Dunlap", but have found a "Thomas Dunlap", seedsman. His 1852 catalogue lists:
Harisonii, Austrian Briar Rose, free golden yellow, semi-double and immense bloomer 1.50 (std) .50 (dwf)

The correct spelling is not proof, of course, but suggests that this Dunlap knew the real Harison.

BTW, Hovey reported that Harison generally knew the seed parent of his Camellias, but neglected the pollen parent.

Prince (1846) wrote, " Rosa Harrisonii, or Harrison's Yellow, was raised from seed by the late Geo. Harrison, Esq., of New-York, from whom I received the first plant he parted with, in exchange for a Camellia Aitoni, which I had just then imported at an expense of three guineas."

I have found that Prince imported an assortment of Camellias, including "Aiton's large single red camellia, $15" and was advertising them in The New England Farmer in October of 1829, and later.
Karl