An Introduction to the Fourth Year of These Tracts

PHILOSOPHICAL TRANSACTIONS. Monday, March 16. 1667. The Contents. An Introduction to the Fourth Year of these Tracts. An Account of the Invention of Grinding Optick and Burning-Glasses of a Figure not Spherical, lately produced before the R. Society. Some Observations by way of Answer to some of the Inquiries concerning Tydes, proposed Numb. 17. and 18. Queries and Directions for the Caribbe-Islands. An Account of two Books: I. SAGGI DI NATURALI ESPERIENZE fatte nell' ACADEMIA del CIMENTO, in FIRZENZE A. 1667. in Fol. II. VERA CIRCULI & HYPERBOLÆ QUADRATURA, in propria sua Proportionis specie inventa & demonstrata à JOCOBO GREGORIO Scoto, PATAVII in 4° 1667: whence a Method is deduced of Measuring the Area of an Ayperbole, and consequently finding the Logarithim of any Number, and é contra: And this applied to the Gauging or Mensuration of any Segment of any Cone, &c. An Introduction To the Fourth Year of these Tracts. In my first Number (of March, in the Year 1665.) I render'd the reasons and purposes of these Philosophical Communications. In the Second Year (beginning in March A. 1666. at Numb. 10.) I endeavour'd to revive and impress the Utility of these United Correspondencies. In the Third year (beginning in March A. 1667. at Numb. 23.) I defended our Industry from the Obloquies of such men, as prefer endless Contentions about words before the useful Works of the noblest Arts; and boast the Notions, yea, and oft-times the Cavils of pore-blind Heathen Writers, above the great and admirable Works of God. Here, I think, I may from manifest appearances, without any great presumption, ominate, That the following Tracts shall somewhat more satisfie the Ingenious, than the former, for as much as my Philosophical Commerce from time to time enlargeth itself, and I am still better and better furnish'd with store of judicious Correspondents in the most considerable places of the World; and they are by the foregoing Tracts (especially from Numb. 11. and several of those that follow) better directed to afford true Aids, as also to send in good Answers to the Enquiries already made publick. Yet I hope, even our former Tracts will not be very much blamed by such, as shall be pleas'd to consider, that some of them have already brought in several pertinent Answers; viz. from a Sea-Voyage, the Caribbe-Islands, and Jamaica in particular, the Baltick-Sea, our Mendip-Mines, &c. Numb. 19, 27, 30; that others of them do instruct, prepare, and enable, for severe Observations; others lay the ground for Philosophical Advancements; others are accurate Exemplifications; and some of them contain divers valuable Particulars, which perhaps had otherwise been lost, or drown'd in a worse crowd of Impertinencies, or scatter'd in more costly Volumes. Certainly there are well-devised Directions, especially proper for Sea-men and all Travellers, and such as may pleasingly and beneficially entertain them whilst they are under Sail, or on their Land-Voyages; and they cannot be unacceptable to the Ingenious and Curious in our Colonies, and in other places of best note. All which may be seen in a short view in the Tables annexed to Numb. 22, and 32.