roL. XI.] 



PHILOSOPHICAL TRANSACTIONS. 



^99 



Further Observations of the Lunar Eclipse* of Jan. 1, 1676, N, S. By M. 

 Bulliald, Riclielt, Hecker, ^c. N° 125, p. 6 10. 



Observed at 



Phases. 



Beginning of eclipse. . . . 

 Greatest obscuration. . . . 



End of eclipse 



Total duration 



Digits eclipsed 



It appears, from these observations, compared with calculations from the 

 then existing tables, that the Rudolphine tables differ considerably from the 

 truth, both for duration and magnitude ; but the Philolaic tables less. 



^n Account of some Books. N° 125, p. 611. 



I. Nicolai Mercatoris Holsati, e Soc. Regia, Institutionum Astronomicarum 

 Libri duo, de Motu Astrorum Communi et Proprio, secundum Hypotheses 

 Veterum et Recentiorum praecipuas; deque Hypothesewn ex Observatis Con- 

 structione : cum Tabulis Tychonianis Solaribus, Lunaribus, Lunae-Solaribus, 

 et Rudolphinis, Solis, Fixarum, et quinque Errantium, earumque Usu, Prae- 

 ceptis et Exemplis commonstrato : subnexa Appendice eorum, quae novissimis 

 temporibus caelitus innotuerunt. Lond. 1676, in 8vo. 



This learned and industrious mathematician comprehends in these institutions 

 the sum and substance of astronomy. And though many authors before him 

 have treated this science well, particularly Maestlin, Kepler, Riccioli, and 

 Gassendi, yet he pursues several things differently from others, and insists on 

 such particulars as he thought most pertinent to his purpose. For besides the 

 chief use of both the globes in some considerable problems, and the trigono- 

 metrical calculation employed in the doctrine of the sphere ; he has fully ex- 

 plained the equation of time, in both the Ptolomaean and Copernican system, as 

 also the lunar hypothesis of Tycho, and the eliptical of the planets : nor has he 

 been less solicitous in teaching how to raise hypotheses from observations, and 

 in delivering the calculus of the celestial motions from the most approved tables: 



* See several other observations of this eclipse, in some of the preceding Numbers. 



act 2 



