Of this no trace remains; but it is established that he was a highly accomplished mathematician, much admired by Kepler; and that he "applied the telescope to celestial purposes almost simultaneously with Galileo" (art. Harriott in Dict. of Nat. Biog.; cp. art. in Encyc. Brit.). "Harriott ... was the first who dared to say A=B in the form A - B = 0, one of the greatest sources of progress ever opened in algebra" (Prof. A. De Morgan, Newton, his Friend and his Niece, 1885, p. 91). Further, he improved algebraic notation by the use of small italic letters in place of Roman capitals, and threw out the hypothesis of secondary planets as well as of stars invisible from their size and distance. "He was the first to verify the results of Galileo." Rev. Baden Powell, Hist. of Nat. Philos. 1834, pp. 126, 168. Cp. Rigaud, as cited by Powell; Ellis's notes on Bacon, in Routledge's 1-vol. ed. 1905, pp. 674-76; and Storojenko, as above cited, p. 38, note. Against the aspersion of Harriott at Raleigh's trial may be cited the high panegyric of Chapman, who terms him "my admired and soul-loved friend, master of all essential and true knowledge," [49] and one "whose judgment and knowledge, in all kinds, I know to be incomparable and bottomless, yea, to be admired as much as his most blameless life, and the right sacred expense of his time, is to be honoured and reverenced"; with a further "affirmation of his clear unmatchedness in all manner of learning." [50]