Page 351 - 89 history of astronomy_opt
P. 351
fractions enabled him to abolish the error
due to our atmosphere so far as it could af-
fect naked-eye observations. The azimuth
circle of Tycho’s largest quadrant had a di-
ameter of nine feet, and the quadrant a ra-
dius of six feet. He introduced the mural
quadrant for meridian observations.[2]
[Illustration: ANCIENT CHINESE IN-
STRUMENTS, Including quadrant, celes-
351
