30. In the thirteenth century, we find Arabian numerals employed in the tables of Alfonso X., king of Castile, published about 1252. They are said to appear also in the Treatise of the Sphere, by John de Sacro Bosco, probably about twenty years earlier; and there is an unpublished treatise, De Algorismo, ascribed to him, which treats expressly of this subject.[265] Algorismus was the proper name for the Arabic notation and method of reckoning. Matthew Paris, after informing us that John Basing first made Greek numeral figures known in England, observes, that in these any number may be represented by a single figure, which is not the case “in Latin nor in Algorism.”[266] It is obvious that in some few numbers only this is true of the Greek; but the passage certainly implies an acquaintance with that notation, which had obtained the name of Algorism. It cannot, therefore, be questioned that Roger Bacon knew these figures; yet he has, I apprehend, never mentioned them in his writings: for a calendar, bearing the date 1292, which has been blunderingly ascribed to him, is expressly declared to have been framed at Toledo. In the year 1282, we find a single Arabic figure 3 inserted in a public record; not only the first indisputable instance of their employment in England, but the only one of their appearance in so solemn an instrument.[267] But I have been informed that they have been found in some private documents before the end of the century. In the following age, though they were still by no means in common use among accountants, nor did they begin to be so till much later, there can be no doubt that mathematicians were thoroughly conversant with them, and instances of their employment in other writings may be adduced.[268] [265] Several copies of this treatise are in the British Museum. Montucla has erroneously said that this arithmetic of Sacro Bosco is written in verse. Wallis, his authority, informs us only that some verses, two of which he quotes, are subjoined to the treatise. This is not the case in the manuscripts I have seen. I should add, that only one of them bears the name of Sacro Bosco, and that in a later handwriting. [266] Hic insuper magister Joannes figuras Græcorum numerales, et earum notitiam et significationes in Angliam portavit, et familiaribus suia declaravit. Per quas figuras etiam literæ repræsentantur. De quibus figuris hoc maxime admirandum, quod unica figura quilibet numerus representatur; quod non est in Latino, vel in Algorismo. Matt. Paris, A.D. 1252, p. 721. [267] Parliamentary Writs, i. 232, edited under the Record Commission by Sir Francis Palgrave. It was probably inserted for want of room, not enough having been left for the word IIIum. It will not be detected with ease, even by the help of this reference.