QUADRANTS n 



house at Oud-Poelgeest, at 52 12' N. latitude. The book was printed 

 at Leyden in 1728 and the tables were prepared by the famous Nic. 

 Cruquius. There is great appropriateness in this instrument having 

 fallen into the hands of the one man who is best qualified to value 

 Boerhaave's work. 



A similar instrument has been figured by Lansberg in 1663. 



Ch. Ch. O.P. 2.13. 



52. Quadrant adapted for use as a Sun-clock. 



From La Siljan, Dalecarlia. Pitt-Rivers Coll. 



ASTROLABES 



Three instruments in the Oxford collections represent the astrolabe 

 in its eastern form. Two of them have a special interest for their 

 personal associations ; the one with Archbishop Laud, the other with 

 John Selden, the latter having been the first to point out the source 

 of Chaucer's thorough knowledge of the astrolabe. These oriental 

 instruments indicate the type from which the Western and English 

 astrolabes were copied and evolved. Indeed, the earlier western 

 instruments differ from their Arabian prototypes in little save the 

 lettering being in western instead of Arabic script. A comparison of 

 the fine astrolabe of 1208, described by Sarrus, with the Laudian 

 instrument, with one of the Merton instruments, and with others in the 

 unrivalled collection of Mr. Lewis Evans shows how little the construc- 

 tion of the instrument has changed in the course of years. 1 



It was from the East that the astrolabe received the decorative 

 quality which it never lost ; even after being reproduced for centuries 

 by European craftsmen. It has always been the most artistic of common 

 scientific instruments. 



53. Arabian Astrolabe. Type of 1224. 

 Diameter 7! inches. 



With eight tablets ; one made for the latitude of Morocco. 



Bodleian Library, MS. Selden Superius, 72. i, S.C. 3205. 

 This beautifully finished instrument came to the University with the 

 Library of John Selden in 1659. 



54. Arabian Astrolabe. Writing of c. 1400. 

 Diameter 6| inches. Bodleian Library. 

 Presented by Archbishop Laud, whose arms impaling Canterbury 



are engraved on the back of the bracket. 



55. Astrolabe (or Saphea) and Quadrant. c. 1340, before 1350. 

 Diameter i3 T 4 o inches. Oriel College. 

 This instrument, and the 1350 Astrolabe in Merton College, belong 



1 See also p. 24. 



