A, D. 1 200. ^6^ 



Norwegians, who had fo juft an idea of its great importance, that they 

 made it the device of an order of knighthood, to be conferred on men 

 of the higheft rank. [T'orfai Hijl. Norweg. L. iv, p. 345.] 



In 1306 Robert king of Scotland, when croffing from Arran to the 

 coaft of Carrick in the night-time, fleered by a fire upon the fhore, 



' For thay na nedil had nor flane,' 

 as is obferved by Barber, his poetical biographer. Hence it appears, 

 that the ufe of the compafs was well known in Scotland, at leaft in the 

 year 1375 *, when Barber wrote, and very probably alfo before 1306. 



Though I have not found any earlier notice of the ufe of the com- 

 pafs among the Englifli f , they muff unqueftionably have known it 

 fooner than the Scots : and we may be alTured, that it was well known 

 to all the fouthern maritime nations, before fuch remote countries as 

 Norway and Scotland had the ufe of it. 



In pi'ocefs of time navigators, or experimental philofophers, difcover- 

 ed, that the polarity of the magnetic needle was not perfedly true, and 

 that it diverged, or varied, fomewhat from the real north point. Suc- 

 ceeding experiments fhowed, that the Farianon was not everywhere the 

 fame ; that there was a Une on the furface of the globe, on which there 

 was no variation ; that on one fide of that line the north point of the 

 compafs varied to the eaflward, and on the other to the weflward, of 

 the true north ; and that the quantity of the variation increafed in an 

 unknown proportion to the diftance from the line of no variation. This 

 irregularity was known in, or before, the year 1269, when Peter Ad- 

 figer wrote upon the various properties of the magnet, the conftrudion 

 of the azimuth compafs, and the variation of the magnetic needle. 

 The difcovery of the variation has, however, been attributed by fome 

 to Chriflopher Columbus in the year 1492, and by others to Sebaflian 

 Cabot in 1500, who may have obtained the reputation of it, becaufe in 

 their voyages, wherein they made more difference of longitude than 

 former navigators, they had more ample opportunities of making ex- 

 periments upon the variation. 



It was afterwards dif covered, that the variation not only differed as it 

 receded eaft or weft from the line of no variation, but that that line it- 

 felf, which was found to be an oblique waving curve, had alfo in the 

 northern hemifphere fhifted to the eaftward of its former ftation. The 

 nice obfervations of the eighteenth century have demonftrated, that 

 the variation is in a progreffive and perpetual ftate of alteration ; and 



* I fay nothing of the Orkney fifliermen, who f Chaucer fays in his yljirolab'te, written in the 



about that time made voyages on the coail of year 1391, that the fhipmen reckon thirty-two 



America with the compafs, according to Ramufio's parts of the horizon, which plainly^ refers to the 



narrative of Zeno's voyage, with Dgftor Forfter's compafs with its mod improved diviiion ; a divifion 



explanation ; becaufe the geography of that voy- of which the people of Bruges in Flanders claim 



age is ftill fomewhat doubtful. See below under the honour of being the authors. 

 the year 1360. * 



