12 G. H. KNIBBS. 



necessity for determining, for the convenience of the devout 

 believer, the direction of Mecca from every part of the wide- 

 extended Moslem dominion, greatly promoted the study of 

 astronomy. Tables and instruments were perfected, observatories 

 erected, observations systematised, and astronomy ardently culti- 

 vated. The first great Arabic author of mathematical books, 

 Mohammed ben Musa Al Kharizmi [about 820 B.C.], has given 

 us the words 'Algorithm' and 'Algebra,' the former being a cor- 

 ruption of his latinised name Algoritmi, the latter of the first 

 word in the title of his algebra. "Aldshebr Walmukabala " or 

 'restoration and reduction.' With 'Omar bin Ibrahim Al Khay- 

 yami, f? 1017 — 1123 A. D.] better known perhaps through his 

 Ruba'iyat, immortalized in English by Fitzgerald, than through 

 his method of solving equations by intersecting conies, the Arabian 

 period culminated. 



In the matter of scientific culture the Arab was liberal, but 

 not inventive. Lacking the penetrative insight, and power to 

 make great and original contributions to Science, he nevertheless 

 was a faithful custodian and a broad disseminator of the intel- 

 lectual possessions of antiquity. But the time seems to have come 

 for the Semitic custody of Aryan culture of both East and West 

 to be restored to Aryan hands. During the decadent period of 

 the Arabian, Great Britain, Ireland, and France had become the 

 locus of mathematical activity in Christian Europe. The centre 

 changed however to Italy with the appearance, at the beginning 

 of the 13th century, of Leonardo of Pisa, who among other things, 

 strongly advocated the adoption of the so-called Arabic notation. 

 In respect of mathematics generally he is said to have treated the 

 rich material before him with skill and euclidean rigour. 



In the European Universities the study of mathematics now 

 began to be promoted, though it must be confessed in a half-hearted 

 manner; for, by the fashion of the time, the energies of the brightest 

 intellects were exhausted on the subtleties of scholasticism. With 

 the fall of the Byzantine Empire in 1453, came, however, a new 

 era. The precious manuscripts of Greek literature were studied 



