Isaac Newton tutvustas 1699. a Kuninglikule Seltsile oma oktanti ehk peegelkvadranti. Newtoni kavandatud mõõtevahend valmis tõenäoliselt juba 1677. a. Mõõtevahendi üksikasjalik kirjeldus anti Edmond Halley kätte, kuid see avaldati alles pärast Halley surma 1742. a. Pole teada, miks Halley seda teavet oma eluajal ei avaldanud, kuna see jättis Newtoni ilma tunnustusest leiutise eest, st tunnustusest, mis omistatakse tavaliselt John Hadley’le ja Thomas Godfrey’le.
Isaac Newton presented his octant or reflecting quadrant to the Royal Society in 1699. Newton's design for the instrument was probably built as early as 1677. A detailed description of the instrument was given to Edmond Halley, but the description was not published until after Halley's death in 1742. It is not known why Halley did not publish the information during his life, as this prevented Newton from getting the credit for the invention that is generally given to John Hadley and Thomas Godfrey.