The True Tragedy of Richard III a source for his play, though the majority tend to favour this judgement. Geoffrey Bullough treats "The True Tragedy" as a "probable source" for "Richard III", citing several commonalities (as when, in both plays, Richard calls for a horse on Bosworth Field, yet refuses to flee the battle) — though Bullough admits that the nature of the plays' relationship is "not clear." The uncertainty in dating has allowed a few commentators to propose a reversed priority, and to argue that the author (or reviser) of "The True Tragedy" may have borrowed from Shakespeare's play. Shakespeare appears to have known of
S-III Saturn I which actually flew, except that the S-V stage was never live. The original Saturn C-2 design would have been S-I stage plus S-III plus S-IV plus, for some missions, S-V. The S-III was to have been a LOX-Hydrogen stage powered by two J-2 engines. The original Saturn C-3 configuration was S-I plus S-II plus S-III plus, for some missions, the S-IV and even S-V. The S-II was to have had four J-2 engines and the S-I would have been upgraded either by increasing the thrust of its eight H-1 engines to 250,000 lb or by replacing the center