( 4*7 ) 
I have been obliged to omit feveral Particulars of kfs 
moment : But thete are the principal Phenomena ; of 
whofe Caufes I fhould have more willingly and with more 
certainty given my Thoughts, if I had had the good luck 
to havefeen the whole from Beginning to end ; and to have 
added my own Remarks to the Relations of others : and 
efpecially if we could by any means have come at the 
Diflances thereof. If it (hall by any be thought a hard 
Suppofition chat 1 affume the Effluvia of the Magnetical 
Matter for this purpofe, which in certain Cafes may 
themfelves become luminous, or rather may fometimes 
carry with them out of the Bowels of the Earth a fort of 
Atoms proper to produce Light in the Ether. I anfwer 
that we are not as yet informed of any other Kinds of 
Effluvia of terreftrial Matter which may ferve for our pur- 
pofe, thanthofe we have here confidered, viz. the Mag- 
netical Atoms, and thofe of Water highly rarified into Va- 
pour. Nor do we find anything like it in what we fee of 
the Celeflial Bodies, unlefs it be the Effluvia proje&ed ouc 
of the Bodies of Comets to a vaft Height, and which 
feem by a Vis centrifuga to fly with an incredible Swift- 
nefs die Centers both of the Sun and Comet, and to go off 
into Tails of a fcarce conceivable Length. What may be 
the Conflitution of thefe Cometical Vapours, we Inhabi- 
tants of the Earth can know but little, and only that 
they are evidently excited by the Heat of the Sun ; where- 
as this Meteor, it I may fo call it, feldom is feen but in 
the polar Regions of the World, and that mod common- 
ly in the Winter Months. But whatever may be the Caufe 
thereof, if this be not, I have followed the old Axiom of 
the Schools. Entia non ejfe temere ncque abfque ncceffitate 
multiplicands 
Laftly I beg leave on this Occafion to mention what, 
near 15 Years fince, l publifh’d in No. 195. of thefe Traffl 
aft ions, viz . That fuppofing the Earth to be concave, 
Uuui with 
