[ 162 ] 
XIV. A Letter from the Rev. Mr. Richard 
Dunthorne to the Reverend Mr. Richard 
Mafon F. R. S. and Keeper of the Wood- 
wardian Mu feu m at Cambridge) concerning 
the Acceleration of the Moon. 
Read 
>749 
June i. 
S 1 R, Cambridge, Feb. 28, 1748-9. 
A FTER 1 had compared a good Num- 
ber of modern Obfervations made 
in different Situations of the Moon and of her Orbit 
in refpeft of the Sun, with the Newtonian Theory, 
as in my Letter of Nov. 4, 1746 I proceeded to 
examine the mean Motion of the Moon, of her Apo- 
gee, and Nodes, to fee whether they were well re- 
prefented by the Tables for any confiderable Num- 
ber of Years, and whether I fhould be able to make 
out that Acceleration of the Moon’s Motion which 
Dr. Halley fufpected. Vide Phil. Tranf. n. 218. 
To this End I compared feveral Eclipfcs of the 
Moon obferved by Tycho Brahe , as they are fet down 
in his Progyninafmata ; p. 1 14, with the Tables *, and 
found them agree full as well as could be expe&ed ; 
confidering the Imperfe&ion of his Clocks, and the 
Difficulty there mud commonly have been in deter- 
mining the Middle of the Eclipfe from the Fafts ob- 
ferved, as publifhed in his Hijloria Codleflis. Indeed 
fmall Diftance of Time between Tycho Brahe 
and 
the 
■ ■■■ 
* . % ) J . « . f . i 
f See thefe Tranfa£h No. 482. p. 412. 
* My Tables corrected as in my former Letter ; which is al- 
ways to be underftood of the Tables mention’d in this. 
