My friend Stephen Smoot has an excellent article (with an equally excellent title!) on figure 7 in facsimile 2 (the hypocephalus) of the Book of Abraham, a depiction of the Egyptian deity Min which Joseph interpreted as ""Represents God sitting upon his throne, revealing through the heavens the grand Key-words of the Priesthood; as, also, the sign of the Holy Ghost unto Abraham, in the form of a dove." It is a very good article and a sound refutation of poorly researched works on the Book of Abraham such as James R. White's anti-LDS tract Min is Not God. Here is Stephen’s article:
As an aside, in his article The Egyptian Pantheon, Joshua J. Mark provides the following information about the deity Min:
Min - An ancient fertility god from the Predynastic Period (c. 6000-3150 BCE). Min was god of the eastern deserts who watched over travelers but was also associated with the black fertile mud of the Egyptian Delta. He is shown as the husband of Isis and father of Horus in early inscriptions and so is associated with Osiris. Min is depicted as a man holding his erect penis in one hand with the flail of authority in the other.