122 PHILOSOPHICAL TRANSACTIONS. [aNNO 1666. 



diction by 69 1 6. Then divide the sum of the products by 7980^ which is the 

 Julian period : the remainder of the division, without having regard to the 

 quotient, will be the year required. 



Ex. gr. Let the cycle of the sun be 3 ; of the moon 4 ; and of the indie- 

 tion 5. Multiply 3 by 4845, and you have 14535 ; and 4 by 4200, which 

 gives 1 6800; also 5 by 69 1 6, which gives 34580. The sum of the products 

 is 65915 ; which being divided by 7980, gives 8 for the quotient, and the 

 number 2075, which remains, is the year of the Julian period. 



An Account of some Booh lately puhlisJied. N" 18, p. 324. 



I. Tentamina Physico-Theologica de Deo, sive Theologia Scolastica, ad 

 Normam Novae et Reformatae Philosophiae concinnata, et duobus libris com- 

 prehensa. 



II. Honorati Fabri, Soc. Jesu Theologi, Tractatus duo ; quorum Prior est de 

 Plantis et de Generatione Animalium ; Posterior, de Homine. 



As the matter of this book is considerable, so is the order and dependence 

 of all its parts excellent; since all the propositions are ranged according to a 

 geometrical method, and so well disposed that the latter always suppose the 

 former, and seem to depend all of them upon certain evident principles, whence 

 they flow by a natural consequence. 



III. Relation du Voyage de I'Eveque de Beryte, par la Turquie, la Perse, 

 les Indes, &c. jusques au Royaume de Siam, et autres lieux ; par M. de 

 Bo urges, Prestre, &c. 



This author, employing his pen chiefly, according to his design, to give an 

 account of the success the undertakers of this voyage had in propagating the 

 Christian faith in the remoter parts of the world, and relating, on that occasion, 

 what number of churches they have founded in Cochin China and the kingdom 

 of Tonquin, in which latter alone he afiirms that there are more than three 

 hundred thousand Christians. 



J Petrifaction. By Mr. Ph. Packer. . N" 19, p- 329- 



Near Wadley, a mile from Farringdon in Berks, there grows an elm containing 

 near a tun of timber, which has now lost the top, and has grown hollow. From 

 the butt of the tree one of the spreading limbs having been formerly cut oft' ..with 

 an axe, that part of the butt, being about l-i- foot above ground, and inward with- 



1. Opus Astronomicon; 2. Nova Geometriae Clavis Algebra 3 3. Tabulae Lodovicaej 4. Diophan- 

 tus Redivivus} and perhaps some others. 



A method of investigating such rules as that above, may be seen in Dr. Hutton's translation of 

 Montucla's Philosophical Recreations, vol. iii. p. 231. 



