SUMMARY OF THE COXTE3TTS. XV 



fraction of rajs. Indian planetary tables. The disturbance in the 

 moon's longitude recognized by Abul Wefa. Astronomical Congress 

 of ToWo, to which Alfonso of CastiDe invited Rabbis aod Arabs, "ob- 

 servatory at Merasha. of Ulogh Beig, the descendant of Timor, at Sam- 

 arcand. and its influence. Measurement of degree in the plain be- 

 tween Tadmor and Bakka. The Algebra of the Arab* has originated 

 rrom two carrenls T Indian and Greek! which long flowed independent- 

 ly of one another. Mohammed Ben Mosa. the Chowarezmier. Dio- 

 phantus, first translated into Arabic at the close of the tenth txaliuj, 

 bjAbol WefaBuzjanL By the same path which brought to the Arabs 

 the knowledge of Indian Algebra, they likewise obtained in Persia and 

 on the Euphrates the Indian numerals and the know! 



ions device of Position, or the employment of the value of position. 

 They transmitted tin* custom to the revenue officers iff Northern Afri-. 

 ca, opposite to the coast* of Sicflj. The probability that the Christians 

 of the West were acquainted with Indian numerals earlier than the 

 Arabs, and that they were acquainted, under the name of the system 

 of die Abacas, with the employment of nine ciphers, according to their 

 position-Tame. The value of position was known in die Suanpan, de- 

 rived from the interior of Asia, as weJLas in the Tuscan Abacas. Would 

 a permanent dominion of the Arabs, *fcg into *rf*m*it their ! 

 exclusive predilection for the ""*C^ (natural, descriptive, physical, 

 and astronomical) results of Greek investigation, bare been beneficial 

 to a general and free mental cultivation, and to die creative power of 

 art ? p. 219-228. 



VI. Period of the great Oceanic Ducomita. America and the Pa- 

 cific. Events and extension of scientific knowledge which prepared 

 the way for great geographical discoveries. As the acquaintance of the 

 nations of Europe with the western portion of the globe constitutes die 

 main object of this section, it is absolute hr necessary to divide in an in- 

 contestable manner die first discovery of America in its northern and 

 temperate zone by die Northmen, from die rediscovery of die same con- 

 tinent in its tropical regions. While die Cafifnte of Bagdad flomahed 

 onder die Abbassides, America was discovered and investigated to die 

 41J north latitude by Leif, the son of Erik die Bed. The Faroe Islands 

 and Iceland, accidentally discovered by Naddod. must be regarded as 

 intermediate stations, and as starting points for the expeditions to the 

 Scandinavian portions of America. The eastern coasts of Greenland in 

 Scoresby's Land (Svalbord), die eastern coasts of Baffin's Bay to TIP 

 55', and the entrance of Lancaster Sound and Barrow's Straits, were 

 all visited Earlier (?) Irish discoveries. The White Men's Land be- 

 tween Virginia and Florida. Whether, prevkiady to Naddod and In- 

 golTa colonization of Iceland, dik island was inhabited by Irish (West, 

 men from American Great Ireland), or by Irish missionaries {Papor. 

 the Cleriei of Dtcuil). driven by the Northmen from die Faroe Islands ? 

 The national treasures of die most ancient records of Northern Europe, 

 endangered by disturbances at home, were tramfaied to Iceland, which 

 three and a hall" centuries earlier enjoyed a free social Constitution, and 

 were there preserved to future ages. We are acquainted with die com- 

 mercial relations existing betw^n Greenland and Xew Scotland (dat 

 American Markland) up to 1347 ; but as Greenland had lost its repub- 

 lican Constitution as early as 1261, and. as a crown fief of Norway, had 

 been interdicted from holding intercourse with strangers, and daere- 

 fore also with Iceland, it is not surprising that Columbus, when be va- 

 iled Iceland in 1477, should hare obtained no tidings of die new cooti- 



