184 



The Variation of the Needle. 



If wo no longer use it in Government work for the original subdi- 

 visions of the public lands, we nevertheless find hundreds of local 

 practitioners of surveying who believe religiously in the ''compass" so 

 reverenced by their fathers, and employ it in private Avork with the 



Thus the courts, at the present day, behold the compass surveyor giv- 

 ing testimony as to chain and needle, distances and bearings, side by 

 side with the skilled engineer with transit and steel ribbon. 



At the present time when modern methods and instruments of pre- 

 cision are employed upon the State work in the tracing out, restoration 

 and monument in g the important ancient boundaries, there is constant 

 occasion for practical study of the magnetic needle, and its variations 

 in order to accurately re-discover the direction and location of the 

 boundaries that are to be restored, and it is thus that I have been led 



In order to recall to mind the principal facts established in regard 

 to terrestrial magnetism, so that the direction and scope of the present 

 discussions may be better understood, a brief statement of the princi- 

 pal conclusions reached by scientific investigators is desirable, and 

 may be best given in the order of their discovery. 



Historical Memoranda. 



Eleven hundred years before the Christian era, the embassadors of 

 Tonquin and Cochin China, guided across the vast plains of Eastern 

 Asia by the floating needles, probably studied and discussed beside 

 their camp-fires, under star-lit skies, the changes in the pointing of 

 the needle; and they were too wise and thoughtful to have attributed 

 the cause to magic or enchantments. Indeed, while Constantine the 

 Great was founding the Empire of the East, Kuopho, a Chinese 

 writer, thoughtfully recorded his opinion that electricity and magnet- 

 ism were controlled by one and the same force; which, " like a mys- 

 terious breath," thoroughly permeated the substances affected. Later, 

 we learn that the Chinese used the suspended needle, and with it 

 observed the decimation from the true north, but passing rapidly on 

 to the year 1492, we reach the striking discovery of the line of no 

 variation, found by Columbus on the 13th of September m that year 

 less than 150 miles west of the Azores, traversing the Atlantic Ocean 

 in a northerly or north-easterly direction. This, first of Agonic lines, 

 Columbus, as its discoverer, proposed as the boundary between the 

 dominions of the Kingdoms of Spain and Portugal, which, enforced 

 by a decree from the Vatican, aroused the greatest interest among 



