Page 166 - 89 history of astronomy_opt
P. 166
His mechanical skill was very great, and
in his workmanship he was satisfied with
nothing but the best. He recognised the im-
portance of rigidity in the instruments, and,
whereas these had generally been made of
wood, he designed them in metal. His in-
struments included armillae like those which
had been used in Alexandria, and other armil-
lae designed by himself–sextants, mural quad-
166
