REFERENCES.--For F. A. Pigafetta, for Petro de Medina and for Martin Cortez, Houzeau et Lancaster, “Bibl. Génér.,” Vol. I. pt. ii. pp. 1221–1223; “New Gen. Biog. Dict.,” Jas. Rose, London, 1850, Vol. XI. p. 113; “Biog. Univ.” (Michaud), Vol. XXXIII. p. 297; “Grand Dict. Univ.” (Larousse), Vol. XII. p. 999; “Nouv Biog. Gen.” (Hœfer), Vol. XL. p. 207. Also Dr. G. Hellmann’s “Neudrucke,” 1898, No. 10, for reproduction of Francisco Falero’s “Tratato del Esphera y del arte del marear” (Del Nordestear de las Agujas), 1535, as well as for reproduction of Martin Cortez’ “Breve Compendio” (De la piedra Yman), 1551. =A.D. 1497.=--Gama (Vasco or Vasquez da), celebrated Portuguese navigator, is known positively to have made use of the compass during the voyage he undertook this year to the Indies. He says that he found the pilots of the Indian Ocean making ready use of the magnet. The first book of the history of Portugal by Jerome Osorius--wherein he gives (pp. 23–24, Book I. paragraph 15, 1581 ed.) a very extended “description de l’aiguille marine, invention des plus belles et utiles du monde”--states that, instead of a needle, they used a small magnetized iron plate, which was suspended like the needle of the Europeans, but which showed imperfectly the north. Gilbert says (“De Magnete,” Book IV. chap. xiii.) that, as the Portuguese did not rightly understand the construction and use of the compass, some of their observations are untrustworthy and that in consequence various opinions exist relative to magnetic variation. For example, the Portuguese navigator Roderigues de Lazos--Lagos--takes it to be one-half point off the Island of St. Helena; the Dutch, in their nautical journal, make it one point there; Kendall, an expert English navigator, makes it only one-sixth of a point, using a true meridional compass. Diego Alfonso finds no variation at a point a little south-east of Cape das Agulhas,[27] and, by the astrolabe, shows that the compass points due north and south at Cape das Agulhas if it be of the Portuguese style, in which the variation is one-half point to the south-east. REFERENCES.--Azuni, “Boussole,” p. 121; Klaproth, “Boussole,” p. 64; Knight, “Mech. Dict.,” Vol. II. p. 1398; Larousse, “Dict.,” Vol. VIII. p. 977; “Voyageurs anciens et modernes” (Charton), 1855; “Le Comte Amiral D. Vasco da Gama,” par D. Maria T. da Gama, Paris, 1902. =A.D. 1497.=--Cabot (Sebastian), a prominent English navigator, lands, June 24, 1497, on the coast of Labrador, between 56 degrees and 58 degrees north latitude.