is true I have in mine own hands an imperfect astronomical manuscript of six sheets of paper, entitled Hypothesis Francelidinis, said to be a piece of a great work of Vieta's, called by him Harmonicum Celeste, which may, perhaps, be found complete in France, whence mine came. I have been told here that the Englishman that, at the time of Vieta's death, served him as a scribe, under the counterfeit name of John Poltrier, being kindly offered by Vieta's heirs to take what he pleased to keep as a remembrance of him, took not a leaf of any of his writings. And Thuanus tells us that the heirs did put all his papers in the hands of Peter Alelmus of Orleans. I never enquired whether this Peter were the father to Jacobus Alelmus, the French king's engineer; from whom, fourteen years after Vieta's death, Alexander Anderson acknowledgeth that he had those two tracts, de æquationum recognitione et emendatione, which he first published at Paris, anno 1615. And though it is likely that Monsieur Aleaume (for so I think the French call him) be now dead, yet I hope a diligent enquirer may learn who was his heir, and what is become of Vieta's Adversaria."