Consult likewise for Abul Wefa: “Le Journal des Savants,” for Nov. 1841, Sept. 1843, Mar. 1845 and Oct. 1871; Houzeau et Lancaster, “Bibliog. Gén.,” 1887, Vol. I. pp. 598–600, and Vol. II. pp. 92–93; “Bull. de la Soc. Acad. de Laon,” Janvier 1903, pp. 40–48; Leopold Von Ranke, “History of England,” Vol. I. p. 367 and notes; Wm. Whewell, “Phil. of the Ind. Sc.,” London, 1840, Vol. II. pp. 386–388; Harold Höffding, “A Hist. of Mod. Phil.,” translated by B. E. Mayer, London, 1900, Vol. I. p. 428. =A.D. 1602.=--Blundeville (Thomas) publishes at London, “The Theoriques of the Seuen Planets,” etc., which, as the lengthy title goes to show, indicates “the making, description and vse of two ingenious and necessarie instruments for sea men to find out thereby the latitude of any place upon the sea or land, in the darkest night, that is, without the helpe of sunne, moone or starre; first invented by M. Dr. Gilbert, a most excellent philosopher, and one of the ordinarie physicians to Her Majestie.” He had previously published, in 1589, “A briefe description of universal mappes and cardes and of their use; and also the use of Ptolemy his Tables,” which was followed, during 1594, by his well-known work on navigation. From the rare sixth edition of the latter (London, 1622) the curious title page is worth reproducing as follows: “M. Blundeville, His Exercises, contayning eight treatises, the titles whereof are set down in the next printed page: which treatises are very necessary to be read and learned of all Young Gentlemen that haue not beene exercised in such Disciplines and yet are desirous to haue knowledge as well in Cosmographie, Astronomie and Geographie, as also in the art of navigation, in which art it is impossible, to profit without the helpe of these or such like Instructions. To the furtherance of which Art of Navigation the sayd Master Blundeville especially wrote the said Treatises and of meere good will doth dedicate the same to all Young Gentlemen of this Realme.” The contents of this curious work treat of Arithmetic, Cosmography, Terrestrial and Celestial Globes, Peter Plancius, his Universal Map, Mr. Blagrau, his Astrolabe, The First Principles of Navigation, etc. etc. The Mr. Blagrau here mentioned is John Blagrave, eminent English mathematician, author of “The Mathematical Jewel,” as well as of “The making and use of the familiar staffe,” of “The Art of Dialling,” and of “Astrolabium Uranicum Generale, a necessary and pleasunt solace and recreation for Navigators in their long journeying, containing the use of an instrument or astrolabe.” From the last named, it appears that Blagrave was a convert to the heliocentric theory of Copernicus (“New Gen. Biog. Dict.,” by Rev. H. J. Rose, London, 1850, Vol. IV. p. 277). The invention of the dipping needle by Mr. Blagrave was before the discovery of the change of the needle’s variation by Mr. Gellibrand (“Philos. Britan.,” Benj. Martin, London, 1771, Vol. I. p. 46).