| |
| |
CATHOLIC ENCYCLOPEDIA: History of Physics |
 | | B.C., and to this geometrician was attributed, although probably erroneously, a "Treatise on Mirrors", in which the principles of catoptrics were correctly set forth. |
| | Dioptrics, being more difficult, was developed less rapidly. |
| | Ptolemy already knew that the angle of refraction is not proportional to the angle of incidence, and in order to determine the ratio between the two he undertook experiments the results of which were remarkably exact. |
| www.newadvent.org /cathen/12047a.htm (15098 words) |
|
