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XVI. A Catalogue of the Immerfions and 
Emerfions of the Satellites 0/ Jupiter, that 
' will happen in the Tear 1750, of which 
there are 173 of the Fir ft, 85 of the 
Second , 94 of the Third, and none of the 
Fourth, by reafon op its great Latitude ; 
in all 322. Computed to the Meridian of 
London from the Flamfteedian Tables : 
Corr ebbed by James Hodgfon F. R. S. 
Mafter of the Royal Mathematical School in 
ChriftVHofpital. 
Note , Thofe that are marked with an Afterifk are vifible at 
London. 
T HE great Improvements made in 
the ufeful Sciences of Geogra- 
phy and Hydrography, by the Obfervations of the 
Eclipfes of Jupiter ' s Satellites, arc too well known 
to need any Account of them, or Encomium upon 
them. They were judged very proper for this Purpofe 
by Galilaus himfelf, who firft discovered them, and 
all the Aftronomers at that time, as being the moft 
certain, fure, and eafieft Method then known, and 
I may venture to fay even to this Time, for as- 
certaining the Difference of Longitudes between 
Places, how remote Soever : And it is this that has 
encouraged PerSons to make conftant Obfervations 
of them : And that they may not neglctt the fre* 
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