Nouvelle carte de la moitie septentrionale du globe terrestre [cartographic material] : montrant la variation du compas, ou le merveilleux accord enchaine des mouvemens regles et ne jamais cessans du vivant pourvoir magnetique; telles qu'on les a trouvez l'an 1750 = Nieuwe kaart van de noordelyke helft des aardkloots : vertoonende de miswyzing van't compas, of de wonderlyke aan-eengeschakelde famenloop, der gereegelde en nimmer stilstaande beweeging der magneetsche levenskragt; zo als dezelve bevonden zyn op 't jaar 1750 = A new map of the northern half of the earth's globe : shewing the variation of the compass, or the marvelous concatenated concurrence of the regular and never ceasing motion of the living magnetick power, as it was found in the year 1750 /

Map of the northern hemisphere on a polar projection showing magnetic variations by isogonic lines. Relief shown pictorially.; Prime meridian: Ferro (Hierro), Canary Islands.; Northern hemisphere sheet one of a pair of separate hemisphere maps of the world by Nicolas van Ewyk.; Scale ca. 1:30 000 000 at the equator.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.map-rm3607