The next witness for Petty—and also against him—is his intimate friend, John Aubrey, the antiquary. Aubrey assisted Anthony à-Wood in the compilation of his "Athenae Oxonienses" by furnishing him a number of "minutes of lives[3]," From his letters to Wood concerning them[4], it appears that Aubrey began his sketch of Petty in February, 1680, and that shortly before March 27, "Sir W. P. perused my copie all over & would have all stand." The chaotic condition of Aubrey's notes[5] renders it impossible to say how much of the manuscript now in the Bodleian Library was approved by Petty; but it seems not improbable that Aubrey showed him folios 13 and 14, bringing the narrative down to Petty's departure for Ireland, 22 March, 1680. If so, we have Petty's approval of the statement (on folio 14) that he was elected professor in Gresham College by the interest of "his friend captaine John Graunt (who wrote the Observations on the Bills of Mortality)[6]." In June, 1680, Aubrey sent this manuscript to Wood[7], but he appears to have recalled it, about ten years later, for the purpose of making additions and corrections. To this later period at least a portion of the memoranda on folio 15 must be assigned, for one of them speaks of certain matters subsequent to Petty's death (1687) which have already escaped Aubrey's memory. It is not so clear that the very incomplete catalogue of Petty's writings on folio 15 was likewise added after the return of the manuscript to Aubrey, since there stand opposite two of the titles mentioned in it notes by Wood telling where copies of the books may be found. Still it is at least probable that this, like what immediately follows it on the same folio, was added by Aubrey after Petty had perused his copy all over. And the probability is heightened by the presence on folio 15 of an assertion directly contradictory to what Petty had approved in 1680. Near the end of the list of Petty's writings Aubrey writes, "Observations on the Bills of Mortality were really his."
The third witness for Petty is Edmund Halley. Halley was the most famous of English students of the Bills of Mortality, and the
