Of course the English _cipher_, French _chiffre_, is derived from the same Arabic word, _a[s.]-[s.]ifr_, but in several languages it has come to mean the numeral figures in general. A trace of this appears in our word _ciphering_, meaning figuring or computing.[221] Johann Huswirt[222] uses the word with both meanings; he gives for the tenth character the four names _theca, circulus, cifra_, and _figura nihili_. In this statement Huswirt probably follows, as did many writers of that period, the _Algorismus_ of Johannes de Sacrobosco (c. 1250 A.D.), who was also known as John of Halifax or John of Holywood. The commentary of {59} Petrus de Dacia[223] (c. 1291 A.D.) on the _Algorismus vulgaris_ of Sacrobosco was also widely used. The widespread use of this Englishman's work on arithmetic in the universities of that time is attested by the large number[224] of MSS. from the thirteenth to the seventeenth century still extant, twenty in Munich, twelve in Vienna, thirteen in Erfurt, several in England given by Halliwell,[225] ten listed in Coxe's _Catalogue of the Oxford College Library_, one in the Plimpton collection,[226] one in the Columbia University Library, and, of course, many others. From _a[s.]-[s.]ifr _has come _zephyr, cipher,_ and finally the abridged form _zero_. The earliest printed work in which is found this final form appears to be Calandri's arithmetic of 1491,[227] while in manuscript it appears at least as early as the middle of the fourteenth century.[228] It also appears in a work, _Le Kadran des marchans_, by Jehan {60} Certain,[229] written in 1485. This word soon became fairly well known in Spain[230] and France.[231] The medieval writers also spoke of it as the _sipos_,[232] and occasionally as the _wheel_,[233] _circulus_[234] (in German _das Ringlein_[235]), _circular {61} note_,[236] _theca_,[237] long supposed to be from its resemblance to the Greek theta, but explained by Petrus de Dacia as being derived from the name of the iron[238] used to brand thieves and robbers with a circular mark placed on the forehead or on the cheek. It was also called _omicron_[239] (the Greek _o_), being sometimes written o or [Greek: ph] to distinguish it from the letter _o_. It also went by the name _null_[240] (in the Latin books {62} _nihil_[241] or _nulla_,[242] and in the French _rien_[243]), and very commonly by the name _cipher_.[244] Wallis[245] gives one of the earliest extended discussions of the various forms of the word, giving certain other variations worthy of note, as _ziphra_, _zifera_, _siphra_, _ciphra_, _tsiphra_, _tziphra,_ and the Greek [Greek: tziphra].[246] * * * * * {63} CHAPTER V THE QUESTION OF THE INTRODUCTION OF THE NUMERALS INTO EUROPE BY BOETHIUS