VOL. XXIX.] PHILOSOPHICAL TRANSACTIONS. 16^ 



angles with the natural direction of the needle we made use of, which was that 

 Dr. Halley had made to observe the variations with. And by means of a 

 carriage contrived for that purpose, the stone was easily moved to and fro, the 

 poles continuing always in the same line. The needle was so placed, that the 

 centre it played on was in the same line with the poles of the stone; the north 

 pole being towards the needle. We measured the distances from the centre of 

 the needle to the extremity of the stone; and found the variations of the 

 needle from its natural position to be as in the following table. 



Qn the Came of the Saltness of the Ocean, and of the several Lakes that emit no 

 Rivers ; with a Proposal, by means thereof, to discover the Age of the fVorld. 

 By Edmund Halley, R. S. Sec. N° 344, p. 296. 



There have been many attempts made, and proposals offered, to ascertain 

 from the appearances of nature, what may have been the antiquity of this globe 

 of earth ; on which, by the evidence of sacred writ, mankind has dwelt about 

 6000 years ; or according to the Septuagint above 7000. But as we are there 

 told that the formation of man was the last act of the Creator, it is no where re- 

 vealed in Scripture how long the earth had existed before this last Creation, 

 nor how long those 5 days that preceded it may be to be accounted ; since we ' 

 are elsewhere told, that in respect of the Almighty a thousand years is as one 

 day, being equally no part of eternity ; nor can it well be conceived how those 

 days should be to be understood of natural days, since they are mentioned as 

 measures of time before the Creation of the sun, which was not till the 4th 

 day. And it is certain that Adam found the earth, at his first production, 

 fully replenished with all sorts of other animals. This inquiry seeming to me 

 well to deserve consideration, and worthy the thoughts of the Royal Society, I 

 shall take leave to propose an expedient for determining the age of the world 

 by a medium, as I take it, wholly new, and which in my opinion seems to 

 promise success, though the event cannot be judged of till after a long period 

 of time; submitting the same to their better judgment. What suggested this 

 notion was an observation I had made, that all the lakes in the world, properly 

 so called, are found to be salt, some more some less than the ocean, which in 

 the present case may also be esteemed a lake; since by that term I mean such 



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