Webster Signature Database - Suggest Correction

Signature Maker Instruments Comments Location References
NUNEZ, PEDRO Portugal, 1542, wrote many books on navigation; invented the "nonius" scale for dividing the quadrant; this was a series of concentric arcs, the outer divided into 90 parts, the second into 89 parts, the third into 88 parts and so on to the innermost arc which was divided into 46 parts; the alidade could thus read to within 30" of arc; Tycho Brahe was the only one to make use of the idea, but not very successfully. Daumas 1.

E-mail address:
Explain your correction here:
To protect against spam entries,
please type the sum of 5 and 2 into this box
(i.e. the number between 6 and 8):