them can be had without the helpes of Astronomie and Cosmographie, much lesse without these two grounds of all artes, Arithmetike and Geometrie: so none of the best learned in those sciences Mathematicall, without conuenient practise at the sea can make iust proofe of the profite in them: so necessarily dependeth art and reason vpon practise and experience. Albeit there are diuers both learned and vnlearned, litle or nothing experienced, which in talke of nauigation will enter deeply and speake much of and against errours vsed therein, when they cannot reforme them. Such also haue written thereof, pretending singular great knowledge therein, and would so be accompted of, though in very deede not worthy the name of good and sufficient pilots. To whom I thinke it shall not be amisse in defence of rules builded vpon reason, and in practise allowed, thus much to say for answere. It is so, that there are rules vsed in nauigation which are not perfectly true: among which the streight lines in sea-cardes, representing the 32. points of the compasse or windes are hot holden to be the least, but noted of such talkers for principall, to condemne the occupiers thereof for ignorant: yet hath the famous and learned Gerardus Mercator vsed them in his uniuersal mappe. But such as condemne them for false, and speake most against their vse cannot giue other that should serue for nauigation to better purpose and effect. Experience (one of the keyes of knowledge) hath taught mee to say it. Wherein with my abilitie, together with some part of my studie, I am rather moued (in this my plot) to make some triall vnto your maiestie: for that I perceiue that such attempts of newe discoueries (whereunto this noble Island is most aptly situated) are by your royall maintenance so willingly furthered: beseeching your highnesse so to accept of these my trauailes, as a pledge of my well willing to my countrey, and of my loyall seruice to your maiestie, whose healthfull happie life and reigne God continue which is Almightie. Amen. Your Maiesties most humble subiect William Burrough. * * * * * The Queenes Maiesties letters to Shaugh Thamas the great Sophi of Persia, sent by Arthur Edwards, William Turnbull, Matthew Tailbois, and Peter Gerard appointed Agents for the Moscouie companie, in their sixt voyage to Persia, begun in the yeere 1579. To the most noble and inuincible Emperour of Persia, King of Shiruan, Gilan, Grosin, Corassan, and great Gouernour of the Indies.