( ><*J ) 
V. Some fymarkf on the Variations of the Magnetical 
Compals publi/bed in the Memoirs of the Royal 
Academy of Sciences, with regard to the General 
Chart of thofe Variations made by E. Halley 5 as 
alfo concerning the true Longitude of the Magellan 
S freights, 
I T mud be acknowledged that the Gentlemen of the Royal 
Academy of Sciences \n France, have, for fome Years pad, 
apply’d themfelves with much Candour, as well as Diligence, 
to examine the Chart I publifh’d in the Year 1701, for (hew- 
ing at one View the Variations of the Magnetical Compafs, 
in all thole Seas with which the Englifh Navigators are 
acquainted : And, to my no fmall Satisfaction, I find that 
what I did fo long ago, has been fince abundantly verified 
by the concurrent Reports of the French Pilots, who of late 
have had frequent Opportunities of enquiring into the 
Truth thereof. So that I am in hopes I have laid a fure Foun- 
dation for the future Difcovery of an Invention, that will be 
of wonderful Ufe to Mankind when perfected; I mean that 
of the Law or Rule by which the (aid Variations change, in 
Appearance regularly, all the World over. Of rhis I have 
adventured long fince to give my Thoughts in N° <48 and 
N° 195 of thefe Tranfatfions, and as yet I fee no Caufe to re- 
tra& what 1 there offer for a Roafonof this Change ; but of 
this we might be more certain, had we a good Collodion of 
Obfervations made in that Ocean which divides Afia and 
America, and occupies about two fifths of the whole Circum- 
ference of the Globe. This, we hope, from the natural 
Curiofity of the French (who want no Means of performing 
it) maybe effectually fupply’d by fuch of that Nation who 
may return from Peru by the Ea[t-lndies, 
z E e 
In 
