rulers, and princes did homage, thither flocked continually from the very corners of the orbis terrarum the many-tongued generation, just rising, or just risen into manhood, in order to gain wisdom." For here it was that Al-Manṣūr and Al-Māmūn and Hārūn al-Rashīd (Aaron the Just) made for a time the world's center of intellectual activity in general and in the domain of mathematics in particular.[[389]] It was just after the Sindhind was brought to Bagdad that Moḥammed ibn Mūsā al-Khowārazmī, whose name has already been mentioned,[[390]] was called to that city. He was the most celebrated mathematician of his time, either in the East or West, writing treatises on arithmetic, the sundial, the astrolabe, chronology, geometry, and algebra, and giving through the Latin transliteration of his name, algoritmi, the name of algorism to the early arithmetics using the new Hindu numerals.[[391]] Appreciating at once the value of the position system so recently brought from India, he wrote an arithmetic based upon these numerals, and this was translated into Latin in the time of Adelhard of Bath (c. 1180), although possibly by his contemporary countryman Robert Cestrensis.[[392]] This translation was found in Cambridge and was published by Boncompagni in 1857.[[393]]

Contemporary with Al-Khowārazmī, and working also under Al-Māmūn, was a Jewish astronomer, Abū 'l-Ṭeiyib,

Sened ibn ‛Alī, who is said to have adopted the Mohammedan religion at the caliph's request. He also wrote a work on Hindu arithmetic,[[394]] so that the subject must have been attracting considerable attention at that time. Indeed, the struggle to have the Hindu numerals replace the Arabic did not cease for a long time thereafter. ‛Alī ibn Aḥmed al-Nasawī, in his arithmetic of c. 1025, tells us that the symbolism of number was still unsettled in his day, although most people preferred the strictly Arabic forms.[[395]]

We thus have the numerals in Arabia, in two forms: one the form now used there, and the other the one used by Al-Khowārazmī. The question then remains, how did this second form find its way into Europe? and this question will be considered in the next chapter.

CHAPTER VII

THE DEFINITE INTRODUCTION OF THE NUMERALS INTO EUROPE

It being doubtful whether Boethius ever knew the Hindu numeral forms, certainly without the zero in any case, it becomes necessary now to consider the question of their definite introduction into Europe. From what has been said of the trade relations between the East and the West, and of the probability that it was the trader rather than the scholar who carried these numerals from their original habitat to various commercial centers, it is evident that we shall never know when they first made their inconspicuous entrance into Europe. Curious customs from the East and from the tropics,—concerning games, social peculiarities, oddities of dress, and the like,—are continually being related by sailors and traders in their resorts in New York, London, Hamburg, and Rotterdam to-day, customs that no scholar has yet described in print and that may not become known for many years, if ever. And if this be so now, how much more would it have been true a thousand years before the invention of printing, when learning was at its lowest ebb. It was at this period of low esteem of culture that the Hindu numerals undoubtedly made their first appearance in Europe.

There were many opportunities for such knowledge to reach Spain and Italy. In the first place the Moors went into Spain as helpers of a claimant of the throne, and