[ 162 3 
X. A Letter from Mr. Peter Wargentin, F. R. S. Secre- 
tary tQ the Royal Academy of Sciences at Stockholm, to 
the Rev. Nevil Mafkelyne, B. D. F. R. S. and AJlro- 
nomer Royal ; concerning the Difference of Longitude of 
the Royal Obfervatories at Paris and Greenwich, refult- 
ing from the Eclipfes of Jupiter’s firfl Satellites , obferved 
during the lajl Fen Tears : to which is added , a Compa- 
rative Table of the correfponding Obfervations of the 
Firjl Satellite , made in the principal Obfervatories. 
Vir plurimum reverende atque celeberrime, 
Read Feb. 6, TPfcETIISTI in utrifque litteris tuis, u ve- 
1777. wf 
“ lim obfervationes fatellitum Jovis, 
“ praecipue primi, a te grenovici, et a Cl. d. messier 
“ parisiis, ab anno 1765 habitas, inter fe conferre, ut 
“ inde eliciatur vera differentia utriufque meridiani:” 
huic defiderio tuo lubens fatisfacio. 
Tuis obfervationibus primi fatellitis non nil! 1 7 cor- 
refpondentes messierii obtigerunt; quarum 8 fuerunt 
inimerliones 
