Note 457 — Chapter IV
Reading edition
The best account I have seen of the invention of the micrometer, is in Mr. Grant's recent work, History of Physical Astronomy, pp. 428, 450–453, where it is proved that Gascoigne invented it in 1639, or possibly a year or two earlier. Compare Humboldt's Cosmos, vol. iii. p. 52; who also ascribes it to Gascoigne, but erroneously dates it in 1640. Montucla (Hist. des Mathémat. vol. ii. pp. 570, 571) admits the priority of Gascoigne; but underrates his merit, being apparently unacquainted with the evidence which Mr. Grant subsequently adduced.