It seems that Dr Zach, a young man, was in England with Count Bruhl, who had married the dowager Lady Egremont.  He thus had easy access to the old Percy Library at Petworth, in Sussex, where was stored, as we have seen by Hariot’s will, the black trunk containing his mathematical writings as bequeathed to the 9th Earl of Northumberland.  In 1785 Dr Zach announced with a truly scholastic flourish in Bode’s Berlin Ephemeris for 1788 his remarkable ’discovery ’ of the papers of Thomas Hariot previously known as an eminent Algebraist or Mathematician, but now elevated to the rank also of a first-class English Astronomer.  The next year, 1786, is celebrated in the annals of English science from the circumstance of Oxford’s having accepted a proposition from Dr Zach to publish his account of Hariot and his writings.  The Royal Academy of Brussels in 1788 printed in its Memoirs Dr Zach’s paper on the planet Uranus, with a long note relative to the discovery at Petworth.

The Berlin paper immediately upon publication was translated into English and extensively circulated in this country, conducing, it is suspected, more to the renown of Dr Zach than to that of Hariot.  In 1793 Bode’s Jahrbuch gave from the pen of Dr Zach an account of the Comets of 1607 and 1618, with Hariot’s Observations thereon.  But these observations were given with so many errors and misreadings, as shown by Professor Rigaud, that they were soon pronounced worthless, to the discredit of Hariot rather than of his eminent editor.  But matters came to a crisis in 1794, nine years after the grand flourish of the first announcement at Berlin.  Dr Zach sent to Oxford for publication his abstract of certain of the scientific papers, and the Earl of Egremont intrusted to the University Dr Zach’s selection of the original papers.  Zach’s abstracts were merely sufficient to identify himself with the works of Hariot, but he had performed no real editorial labours, and had not ’pen’d the doctrine ’ contained in them.  Here were years of useful work to be done which the University dreamed not of, so the whole matter was referred to Professors Robertson and Powell, who both reported adversely in 1798, or before.  In 1799 all the Hariot papers were returned to Petworth.

In the mean time the full translation of Dr Zach’s account of his ’ discovery,’ with some curious additions, found its way into Dr Hutton’s Dictionary of Mathematics, under Hariot, 1796, 2 volumes in quarto.  This publication gave an air of solemn record and history to the transactions, insomuch that Oxford began to be blamed for withholding from the press Dr Zach’s great work.  Oxford preserved a becoming silence.  In 1803 Dr Zach published at Gotha in his Monatliche Correspondenz a fragment of that remarkable letter from the Earl of Northumberland to Hariot (which letter we have shown to be Lower’s, see p. 120).  This publication, together with the reprint of the original Berlin paper by Zach in the second edition of Hutton’s Dictionary in 1815 without alteration, seemed to bring the matter to a point.  Oxford was obliged to rise and explain.