Page:Philosophical Transactions - Volume 002.djvu/32

 Num. 24.

Munday, April 8. 1667

Hough the Art of Navigation, one of the most useful in the World, be of late vastly improved, yet remain their many things to be known and done, the knowledg and performance whereof, would tend to the accomplishment of it: As the making of exact Mapps of all Coasts, Ports, Harbors, Bayes, Promontories, Islands, with their several Prospects and Bearings; Describing of Tydes, Depths, Currents, and other things considerable in the Seas: Turnings, Passages, Creeks, Sands, Shelves, Rocks, and other dangers: Nice Observations of the Variations Rh