C 20 4 ] 
in the Name, for it is not diftinctly wrote in the 
Letter), which contains a Hiftory of Aftronomicat 
Obfervations. M. le Monnier fays, That he infilled 
ftrongly on publifhing a good Tranflation of that 
Book. And as fuch a Work would contribute 
much to the Improvement of Aftronomy, 1 fhou'd 
be glad to fee it publifh'd. I am very impatient to 
lee fuch a Work which contains Obfervations, that 
are not fo old as thofe recorded by Ptolemy . For 
having carefully examined the modern Obfervations 
of the Sun with thofe of fome Centuries paff, al- 
though I have not gone farther back than the fif- 
teenth Century, in which I have found Walt her’ s 
Obfervations made at Nuremberg-, yet I have obferved 
that the Motion of the Sun (or of the Earth) is 
fenfibly accelerated fince that Time ; fo that the 
Years are fhorter at prefen t than formerly : The 
Reafon of which is very natural ; for if the Earth, in 
its Motion, fufrcrs fome little Refinance (which can- 
not be doubted, fince the Space through which the 
Planets move, is neceffarily full of fome fubtile Mat- 
ter, were it no other than that of Light) the Effed 
of this Reiiftance will gradually bring the Planets 
nearer and nearer the Sun 5 and as their Orbits there- 
by become lefs, their periodical Times will alfo be 
diminifh’d. Thus in Time the Earth ought to come 
within the Region of Venus , and in fine into that 
of Mercury , where it would neccflarily be burnt. 
Hence it is manifeft, that the Syftcm of the Planets 
cannot laft for ever in its (prefent) State. It alloin- 
conteftably follows, that this Syftem mud have had 
a Beginning : For whoever denies it, mud grant me, 
that there was a Time, when the Earth was at the 
Diftance 
