656 PHILOSOPHICAL TRANSACTIONS. [aNNO 1702. 



serving the needle's variation from the true north ; and though no doubt notice 

 has been given many times what the variation has been at such times ; yet I 

 doubt no register has been kept of such observations, whence we might form a 

 scheme to know how such variations proceed from time to time. 



It has been observed also of what is called the dipping needle, that, besides 

 the horizontal direction towards the north, it has also a direction of altitude, 

 above and below the horizon, if balanced on a horizontal axis : pointing as it 

 were with its northern end, in our climate, to some point within the body of 

 the earth. Whether or no this direction varies from time to time, like that of 

 its horizontal position northward, I cannot tell ; nor do I know whether it has 

 yet been observed ; nor whether the southern end in other parts of the world 

 dips ; as the northern end does with us. All which things deserve serious con- 

 sideration. 



I could wish that you yourself would take some pains, for I know not who 

 can do it better, or whom else you shall think fit to associate, to collect, and 

 give us a brief history of what has been done in this kind, how, when, and by 

 whom ; and by what steps the doctrine of the magnet has been gradually pro- 

 moted : for it is pity the memory of it should be lost. And perhaps it may be 

 the last request I may live to beg of you, being now at the age of 86 ; and it is 

 for the public, and not for myself. Or if it be too great a task for you to 

 undertake at present, having your hands full of other weighty business ; I wish 

 the Royal Society would seriously recommend it to the care of some other fit 

 person of their members, who may be able and willing to undertake it : as a 

 thing that would be welcome to the inquisitive world, would be an honour to 

 the nation, to Gresham College in particular, and to the Royal Society. 



I have, in the letter abovementioned, given my conjecture, that the mariner's 

 compass was originally an English invention. Not only because England was 

 at that time as famous for navigation, as any nation that I know, for the Hol- 

 land sea-trade was not then in being, nor for a long time after ; but even from 

 the name of mariner's compass, for what in Latin is called circulus nauticus. 

 For the word compass is an ancient English word, for what we otherwise call by 

 a French name, a circle. And I am sure that within my memory, in the place 

 where I was born and bred, it was wont to be commonly so called, though in 

 latter times the word circle is more in use. And if we consult Minshew's 

 Dictionary, we shall find that he takes circle and compass indifferently to 

 signify the same with circulus. And hence it is that circinus is in English 

 called a compass, or a pair of compasses, being the instrument by which we 

 describe a compass or circle. Now I do not know that the word compass then 

 was, or now is, in any other language, so used for a circle indefinitely, or for 



