Hadley's quadrant came thirty years after Dampier, who must have used Davis' instrument, then about ninety years old.
"The Naval Pioneers of Australia and Walter Jeffery" by Louis Becke
Thomas Godfrey, a self-taught mathematician, great in his way, and afterward inventor of what is now called Hadley's Quadrant.
"Autobiography of Benjamin Franklin" by Benjamin Franklin
STATE-STREET, 1 best brass Sextant, latest improvement; Hadley's Quadrants, Davis' do.
"The Olden Time Series, Vol. 4: Quaint and Curious Advertisements" by Henry M. Brooks
In 1731 an account of the reflecting or Hadley's quadrant appeared in a paper given by a member of the Royal Society.
"How Britannia Came to Rule the Waves" by W.H.G. Kingston
With Hadley's quadrant, latitude could be determined within a minute, that is to say, to the third of a league.
"Celebrated Travels and Travellers" by Jules Verne
The mariner's astrolabe was superseded by John Hadley's quadrant of 1731.
"Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 7" by Various
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