282 POPULAR LECTURES AND ADDRESSES. 



" are first found by means of the mariner's com- 

 " pass, and when the height of the tide and times 

 " of high-water have been found when the moon's 

 " position was on this or that * point of the 

 " compass ' (as they call it), it is incumbent to 

 " inquire particularly in what region, or according 

 " to the usage of what region, that particular 

 " compass was made by which those directions of 

 " places and those times of tides w r ere first 

 " observed. For, any one who with a British 

 " compass should follow tables of sailing directions 

 " published for the Mediterranean Sea must be led 

 " very far out of his straight course. So also, he 

 " who in British, or German, or Baltic waters, uses an 

 " Italian compass with the marine charts published 

 " for those places, will often be led out of his right 

 " way. Those differences in the compasses of 

 " different places were made for the purpose of 

 " avoiding error on account of the different vari- 

 " ations in different parts of the world. Yet Peter 

 " Nonius has sought for the meridian by the 

 " mariner's compass or fly (versormm\ as the 

 " Spaniards call the needle, taking no account of 



