Machine summary:
At the time of the zenith of their development, the countries of Islam were the centre of art and learning, a nucleus to which scholars from all parts of the world came to drink from the fountain of learning and science, while the schools of Baghdad and Cordova were the torch-bearers of civilisation when Europe was entangled in the evils of the Dark Ages.
al-Farrukhan, a friend of Yahya al-Barmaki, was one of the engineers and architects of Baghdad; he translated into Arabic some works from the Persian and annotated the Q1wdripartiiwn of Ptolemy.
A description is given in Sir Thomas Arnold's Lt:>gw:y of Islam in the following words: "Al-Ma'rnun had a degree of meridian measured in the plain of Sinjar by a method different from thar of the Greeks: a number of observers setting out from the same point walked.
An example of the beautiful demon• stration is given below : To solve the equation : a square and 10 roots arc equal to 39 dirhams, (x'.
wrote on meteorology and optics, his works in later times being translated into Latin.
He was a great philosopher and wrote a treatise on the theory of music; in this work can be found the origin of logarithms.
In addition to this, the Arabs at that time had an advanced know• ledge of the conics, like the problem of the two proportional means, the trisection of an angle, the construction of regular polygons and specially the enneagon, Several solutions of the trisection of an angle were known to theArabs.