To protect our indiscretions from the profanities of the mysterious (3)

The history of the Antient and Primitive Rite is tortuous, tortured and largely mythical

J.M. Hamill, "John Yarker: Masonic Charlatan?" — Ars Quatuor Coronatorum, no. 109 (1996).

The amount of hedging and vagueness in the brief account of the history of the Rite of Memphis and A. & P. Rite prefaced to the Manual of the Degrees reflects the sketchy and frequently contradictory nature of the accounts of the rites which I have managed to find in printed and online sources (the Wikipedia pages in particular are poorly-sourced and appear to have been a victim of edit-warring).

For instance, the date for Marconis handing over control of the Rite of Memphis to the Grand Orient of France is variously given as 1852 and 1862; the G.O. is variously characterised as having Memphis "effectively closed down," forbidding working all but its first three degrees, or mandating the reduction of the 90+ degrees to 33; some commentators on the Rite have questioned whether Seymour actually received a character from Marconis making him 96° and authorising him to establish the Rite in the U.S.A.  Hamill (op. cit.) ascribes the reduction to Marconis; the anonymous author of the "Publisher's Introduction" to a reprint (1990s) of an English translation of Marconis' Sanctuary of Memphis claims that Seymour was responsible for the reduction and speculates that he was motivated by a desire to compete with the Ancient and Accepted Scottish Rite (who expelled him in 1865).  Still others state that Seymour was not merely expelled from AASR by the Supreme Council, Northern Masonic Jurisdiction, but also kicked out of the Cerneau group he subsequently joined (of course, it is possible that this was after said Cerneau group was absorbed by the "regular" NMJ Supreme Council).

Yarker had apparently at some point by 1876 obtained an authority for the Rite of Mizraim of 90°; this was originally distinct from the Rite of Memphis, indeed the two were frequently at odds; Marconis repeatedly denounced Mizraim in his Sanctuary of Memphis.  Be that as it may, an account of the Mizraim degrees of unclear provenance, in Internet circulation as scans of a printed text, is prefaced by an edict from Yarker authorising conferring of Mizraim degrees by name upon members of his A. and P. operation (the 4°-46° on 11°s, the 47°-66° on 20°s, the 67°-86° on 30°s and the final four degrees on members of the roughly corresponding official grades 31°-33° of the A. and P. system).

For the record, Hamill's study of Yarker in AQC concludes by answering the question posed by its title with a firm negative.

"The charge of being a degree-monger was a spiteful slur on his character put about by those who did not know him. [...] A charlatan is by definition dishonest, the last word that could be used against Yarker."