12 > PHILOSOPHICAL TRANSACTIONS. [aNNO 1672. 



Ejusdem Doctoris JVaUlsii non nulla, De Cenlro Gravitatis Hyperhohej Pn^gressce 

 Epistolce suhnexa. N° 87, p. 5074. 



These intricate algebraical expressions and calculations, relating to the centre 

 of gravity, have been properly superseded by tHe easy method of fluxions, since 

 happily invented. 



j4n Jlccount of some Books. N° 87, p. 5076. 



I. Tractatus de Natura Substantise Energetica, seu de Vita Naturae, ejusque 

 Tribus primis Facultatibus ; Perceptiva, Appetitiva, Motiva, &c. Auth. Franc. 

 Glissonio, Med. D. et P. et Coll. Med. Lond. Socio, nee non Societatis Re- 

 galis Collega. Lond. An. 1 672, in 4to. 



This metaphysical tract is not interesting to philosophers of the present day. 



II. Jeremiae Horroccii* Angli Opera Posthuma : una cum Guil." Crabtraei 

 Observationibus Coelestibus; nee non Joh. Flainstedii de Temporis ^quatione 



* This splendid genius was born at Toxteth in Lancashire, about the year 1619. From a gram- 

 mar school in the country, he was sent to Cambridge, where he spent some time in academical 

 studies. He began at 14 years of age to apply to the study of astronomy j but from his want of 

 books, and tlie moderate circumstances of his father, he could make but small progress in it. About 

 3 years after he formed an acquaintance with Mr. Wm. Crabtree, of Broughton near Manchester, 

 who was also engaged in the same studies, and with whom a correspondence was carried on till his 

 death. Thus encouraged, young Horrox assumed new vigour, procured other books and instruments, 

 and was pursuing his studies and observations with great assiduity, when his progress was suddenly 

 arrested by the hand of death, the 3d of Jan. l6'40, in the 22d year of his age. 



What we see of his wridngs, in the book noticed in this article, is sufficient to show how great a 

 loss the world- had by his death. He had just finished his " Venus in Sole visa," 1639, a little be- 

 fore. This was published in 1668, by Hevelius, as above noticed. His other posthumous works, 

 or rather his imperfect papers, were published by Dr. Wallis, as stated in the article above, with 

 some account of his lifej in which we find he first asserts and promotes the Keplarian astronomy 

 against the hypothesis of Lansberg ; which he proves to be inconsistent with itself, and neither agree- 

 ing with theory nor observations. He vindicates Tycho Brahe fi-om some objections made to his 

 hypothesis, and gives a new theory of the moon ; to which are added the lunar numbers of Mr. 

 Flam steed. There are also extracts from several letters between him and Mr. Crabtree, on various 

 astronomical matters ; witli a catalogue of astronomical observations. 



There are two things particularly which will perpetuate tlie memory of tliis very extraordinary 

 young man. The one is, that he was the first person that ever predicted or saw the planet Venus in 

 the sun. Though he was not aware of the great use that was to be made of it, in discovering the 

 parallax and distance of the sun and planets, yet he made from it many useful observations, corrections, 

 and improvements in the theory of the motions of Venus. Secondly, his new theory of lunar mo- 

 tions ; which Newton himself made the ground work of all his astrononiy, relative to the moon ; and 

 who always spoke of our author as a genius of the first order. ^ 



