274 PHYSICAL SCIENCE IN THE MIDDLE AGES. 



became pope, by the name of Sylvester II. Among 

 other cultivators of the sciences, some of whom, 

 from their proficiency, must have possessed with 

 considerable clearness and steadiness the elemen- 

 tary ideas on which it depends, we may here men- 

 tion, after Montucla 13 , Adelbold, whose work On 

 the Sphere was addressed to Pope Sylvester, and 

 whose geometrical reasonings are, according to 

 Montucla ", vague and chimerical; Hermann Con- 

 tractus, a monk of St. Gall, who, in 1050, published 

 astronomical works; William of Hirsaugen, who 

 followed this example in 1080 ; Robert of Lorraine, 

 who was made Bishop of Hereford by William 

 the Conquerpr, in consequence of his astronomical 

 knowledge. In the next century, Adelhard Goth, 

 an Englishman, travelled among the Arabs for 

 purposes of study, as Gerbert had done in the 

 preceding age; and on his return, translated the 

 Elements of Euclid, which he had brought from 

 Spain or Egypt. Robert Grostete, Bishop of Lin- 

 coln, was the author of an Epitome on the Sphere ; 

 Roger Bacon, in his youth the contemporary of 

 Robert, and of his brother Adam Marsh, praises 

 very highly their knowledge in mathematics. 



" And here," says the French historian of mathe- 

 matics, whom I have followed in the preceding 

 relation, "it is impossible not to reflect that all 

 those men who, if they did not augment the trea- 

 sure of the sciences, at least served to transmit it, 

 13 Mont. i. 502. " Mont. i. 503. 



