He wrote also treatises on the astrolabe (a copy of this is in the British Museum), on the abacus (three copies exist in the Vatican library, the library of Leiden University and the Bibliotheque Nationale in Paris), translations of the Kharismian Tables and an Arabic Introduction to Astronomy.
Amongst them may be mentioned a history of the dispute with Palamas; biographies of his uncle and early instructor John, metropolitan of Heraclea, and of the martyr Codratus of Antioch; funeral orations for Theodore Metochita, and the two emperors Andronicus; commentaries on the wanderings of Odysseus and on Synesius's treatise on dreams; tracts on orthography and on words of doubtful meaning; a philosophical dialogue called Florentius or Concerning Wisdom; astronomical treatises on the date of Easter and the preparation of the astrolabe; and an extensive correspondence.
- Persian Astrolabe (c.1712) Inscribed In Arabic.
Two treatises on mathematics are ascribed to him: A Commentary on the Mathematics of Nicomachus, edited by Hoche (1864 and 1867), and a Treatise on the Use of the Astrolabe, published by Hase.
In Astrolabe i Bay the limit is 6; with the more degraded tribes it is 3, or, as in Torres straits, they have names only for 1 and 2; 3 is 2 +1.
- Mariner's Astrolabe, A.D.
Chaucer wrote a treatise on the astrolabe; Milton constantly refers to planetary influences; in Shakespeare's King Lear, Gloucester and Edmund represent respectively the old and the new faith.
In 1827 Dumont d'Urville in the "Astrolabe" surveyed them much more accurately, but the first thorough survey was that of the United States exploring expedition in 1840.
At Humboldt Bay the people are ready to trade, as are the tribes at Astrolabe Bay; here the Russian Miklucho Maclay lived for some time, and was favourably impressed by the natives.
- Chaucer, Treatise on the Astrolabe (Skeat's edition of Chaucer); J.
Morley, Description of Astrolabe of Shah Husain; M.
The astrolabe quadrant or cross-staff enabled the mariner to determine"his latitude with a certain amount of accuracy, but for his longitude 1 See fig.
Gradually, from Eratosthenes to Tycho, Hipparchus playing the most important part among ancient astronomers, the complex astrolabe was evolved, large specimens being among the chief observa tory instruments of the 15th, 16th and even 17th centuries; while small ones were in use among travellers and learned men, not only for astronomical, but for astrological and topographical purposes.
The naming of the intermediate subdivisions making up the thirty-two points or rhumbs of the compass card is probably due to Flemish navigators; but they were recognized even in the time of Chaucer, who in 1391 wrote, "Now is thin Orisonte departed in xxiiii partiez by thi azymutz, in significacion of xxiiii partiez of the world: al be it so that ship men rikne thilke partiez in xxxii" (Treatise on the Astrolabe, ed.
(2) The mariner's astrolabe, fig.