VOYAGES OP THE CABOTS IN 1497 AND 14!)8. 57 



III tliis portion of 1113^ paper, then, Peter Martyr, Gomara, Ramiisio and Ilakluyt are of 

 minor importance. I am to concern myself first with those Spanish and Italian envoys 

 whose lettei's and despatches from England in that same year are almost the only contem- 

 porary evidence we possess of John Cabot's achievement. As these were all written before 

 the return of the second expedition, in studj'ing them we are sure of having the only extant 

 information concerning the first voyage absolutely free from any intermixture with the 

 details of the second. 



IV. Variation of the Compass in 1497. 



Thus far I have been considering the two Cabot voyages together, in their contrasts ; 

 and now I shall endeavour to detach them the one from the other in all the details which 

 remain of record ; but, before doing so,' some attention must be devoted to the mariner's 

 compass as then in use, for it was then, as now, the reliance of all sailors in unknown seas. 

 I should never have attempted even to refer to so difiieult a (piestion, had it not Ijeen for the 

 reports of the United States Coast and Geodetic Survey for 1880 and 1888 which contain 

 papers by Mr. Chas. A. Schott and Capt. Fox. By the aid of those very valuable papers it 

 became possible to form an intelligent opinion as to what can and what cannot be known 

 about the variation of the compass in the îiorth Atlantic in 1497. 



The mariner's compass had been in use in Europe since the middle of the 12th century. 

 At the time of Columbus and Cabot it was, in all essential parts, like that now in use. The 

 card was divided into 32 points of 11} degrees each. It had been observed that the needle 

 did not point exactly to the pole star : but the variation was tln'U ycvv slight ; in southern 

 and western Europe only al>out 5 ; or less tlian half a jioiiit. What variation thei'c was 

 was to the east of north and it was supposed to be constant ; hence, when, on his first voyage 

 to America in 1492, Columbus noticed that the needle crossed over to the west, one-half 

 point in the eVening and another half point the next morning, he was very much astonished ; 

 and when, four days later, on Septemlier 17th, his pilots noticed it their hearts sank \\itli 

 aiiprehension at entering a world of waters where even the magnetic needle might become a 

 treacherous guide. This observation by Columbus we may well understand was a very 

 serious and solemn one ; and it fixes beyond all doubt the meridian of no variation at a point 

 west of the Azores, in latitude 28° N. and limgitude about 28° W. At the present time the 

 variation at the point of first notice is 25 degrees or nearly double that observed by 

 Columbus and it therefore follows that all over the ÎSTorth Atlantic, the compass marked in 

 1497 a much less westerly variation than it does now. From this first oliservation, and 

 from the long series of observations since made with increasing accuracy and frcrpieiicy, it 

 has been ascertained that, subject to local conditions, there is a slow swing of the magnetic 

 meridian from east to west and vice versa extending over centuries of time. This has lieen 

 called the secular variation of the compass. Its cause is not known, its laws are not fully 

 ascertained, but it is a fertile source of confusion among students who plot out early voyages 

 in nortliern seas solely with the aid of modern maps. 



"While Columbus, sailing on the latitude of 28-, was proceeding always in the direction 

 where the variation was slight, Cabot's course in the north was in a region of greater 

 variation ; being so much the nearer to the magnetic pole. For Columbus was sailing on a 

 west course which he scarcely deviated from, because although on the last three days of the 

 voyage he steered S. "W"., and W. S. W., there were previous days when he made a little 



Sec. 11., 1894. 8. 



