\OTKS. 



AS I R()\( )M\. 



My A. C. 1). (."RoMMiil.lN. B.A., D.Sc, F.K.A.S. 



TAHLi:s or J L' PITER'S SATELLITES.— There was 

 an unanswered <]iiery in " KNcnvi.KDGIi " some months ago, 

 iniiuirin^ how the configuration of Jupiter's satellites could be 

 obtained for other limes than those given in The Nautical 

 Altiianac. If one neglects the mutual perturbation of the 

 satellites, the problem is not a diflicult one. Some simple 

 tables have appeared in the Bolctin dc la Socicdad 

 Astroiioiiiica dc Mexico for June and July last, by Senor 

 En/o Mora. I think that the portion of these tables that is 

 required for giving the abscissa of each satellite {i.e., the 

 apparent distance east or west of Jupiter's centre in terms of 

 the planet's equatorial radius) will be of interest to a sufficient 

 number of our readers to justify its reproduction here. The 

 time for which the positions are required is to be expressed in 

 Greenwich Mean Time (Day commencing at noon, as is the 

 usage in astronomical reckoning). Then the six quantities, 

 I, II, III, IV, m, n, are to be found by adding the quantities 

 from the tables Ai, A., A:i, Ai. A,-,, with arguments century, 

 year of century, month, day of month, hour. 



Table Aj. 



Table Aj 



