A briefe description of vniuersal mappes and cardes, and of their vse and also the vse of Ptholemey his tables. Necessarie for those that delight in reading of histories: and also for traueilers by land or sea. Newly set foorth by Thomas Blundeville, of Newton Flotman in the countie of Norffolke. Gent.

A DESCRIPTION OF GEMMA FRIZI∣us his Instrument called Quadratum Nauticum.

THis square by 2 right lines cal∣led Diameters crossing one ano∣ther with right angles in the ve∣ry Center is deuided into foure Equall quarters, and within the said square vpon the said Center is drawne a Circle, which by meanes of the two foresaid Dia∣meters is also deuided into foure Quadrants, and euery Quadrant is subdiuided with right lines into 8 partes, so as in all, there be 32 lines, signifiyng the 32 winds of the Mariners Compasse. E∣uerie line hauing his proper name of wind written ther∣on. And note that the right line which is drawne right downe in the middest of the square, signifieth the Meridi∣an, shewing the Northpoint aboue, and the South point beneath, and the other right line, crossing the same in the Center, signifieth the Equinoctial line, which sheweth the East point on the right hand, and the West point on the left hand, and the Circle it selfe signifieth the Horizon.

Now you haue to vnderstand, that from the Equinoc∣tiall line vpwards the 2 sides of the square are deuided each of them into 90 degrées of North latitude, and the other two sides from the Equinoctiall downeward, are likewise deuided on both hands into 90 degrées of south latitude. Then the head or front, & also the base of the said square is deuided in the middest by the foresaid Meridian line into 2 equall parts, wherof the first procéeding from the said Meridian towardes the right hand is deuided as well aboue as beneath into 90 degrées of longitude, and that is called the East longitude, and the other part pro∣céeding from the said Meridian towardes the left hand is likewise deuided as well aboue as beneth into 90 degrées

of longitude, & is called the West longitude. The vse of which instrument is thus: first knowing by some table or Mappe, the longitude and latitude of two places, take the difference of both by substracting the lesser out of the gre∣ter. And if the longitude of the second place bee greater then the first, séeke the difference thereof in the front, and also in the base of the East longitude on the right hande. But if the longitude of the second place be lesse then the first, then séeke the difference thereof in the West longi∣tude on the left hand. And here as before I meane by the first place that from whence you goe, of which 2 places, the first is alwaies supposed to bee in the very center of the Circle, and the other is to be found out thus: first, ha∣uing sought out the degrées of the difference of the longi∣tude, as well in the vpper part as in the nether part, and marked the same with one pricke aboue, and another be∣neath, applie your Ruler or a thread to those 2 pricks, or els drawe a secret right line from the one pricke to the o∣ther by a ruler. That done, séeke out the difference of the 2 latitudes on both sides of the square, that is to say, if the second place hath greater latitude then the first, then you must seeke the difference in the North latitude, if lesse, then seeke that in the South latitude. And hauing mar∣ked the same on both hands, by setting down on each side a pricke, drawe a secret right line from marke to marke, and where the last line crosseth the first line, there make a marke, for there standeth the place whereto you would goe. Which if you would know how it beareth from the first place, then lay your ruler both to the Center and al∣so to that marke, drawing a right line passing through the Center, and also through the said marke from the one side of the circle to the other, or els stretch a thred through the Center and the marke, and on that side that the mark is, you shall sée the name of the winde that sheweth how the second place beareth from you, the opposite point whereof is the winde whereby you haue to saile. As for ex¦ample,

if you would knowe howe Venice beareth from London.

Nowe if you séeke in the Mappe, you shall find Lon∣don to haue in longitude 23 degrees and 0 minutes, and in latitude 51 degrees, and 32 minutes. Againe, you shall finde Venice to haue in longitude 36 degrees, and 30 minutes, and in latitude 45 degrees and 15. minutes or there abouts.

The difference of the longitudes is 13 degrees and 30 minutes, which because the longitude of Venice is greater then the longitude of London, you must seeke it out in the East longitude on the right hand, and marke the same both aboue and beneath. Againe, the difference of latitude is 6 degrees and 17 minutes. Which because Venice hath the lesser latitude, séeke that out in the South latitude, marking the same on both handes. That doone, laie two threads, or els drawe two right crosse lines from the foresaid markes, and where those two threads or lines doe crosse, make a marke, which marke signifieth the place whereunto you would goe▪ which is Venice.

Then from the one side of the Circle to the other, lay a ruler or thread passing through the center, and the said marke made for Venice, at the end of which thread, ruler, or line on the right hande you shall sée the winde which sheweth how Venice beareth from London, and on the left hand y^e wind, wherby you haue to saile, if y^e space betwixt y^e 2 places were al sea. For in sailing by sea, you may not thinke to go alwaies by a right line, but often to chaunge your course according as either mainland, hedlands, Iles Currents, Sandes, Rockes, or such like impedimentes shall giue occasion: and therfore though your right course from London to Venice is to go Southwest and by East, yet being come out of the Thames to Douer, your course from thence to the Cape of Britaine is west Southwest. And from thence to the Cape Finis terrae in Spaine, it is

Southwest and by South. And from thence to the cape saint Vincent in Portugale you go right South: and from thence to Gibralter almost East Southeast. Againe from Gibralter to the South point of Sardignia, your course is almost East and by North. And from thence to the south point of Sicilia almost East Southeast: and from thence to Corfu, your course is iust Northeast, and from thence to Venice, you turne againe Northwest.

Thus you see that in going by Sea, one course doth not holde, no nor yet in going by Land, sith Mountaines, Riuers, and lakes may put you out of your right course, and yet it is necessary to know how the place wherto you go, beareth from you to the intent that being out of your way, you may alwaies the better direct your course right againe to the same.

Moreouer, Gemma Frizius sayth, that by this Instru∣ment you may also finde out the difference of longitude betwixt the two places from whence and whither you goe, so as you know before how the second place beareth from the first, and also the difference of their latitudes. As for the latitude of each place, you may easily finde the same with your Astrolabe, Quadrant, or crosse staffe, by taking therewith the Meridian altitude of the Sunne, or the highest altitude of some starre that you know: The order whereof I haue set downe in my Sphere. And the Coast of the Countrey and place whereunto the Shippe is to bee directed, is commonly well knowen to the Ma∣riners how it beareth from the first, and specially hauing a prosperous wind.

Then knowing these two things, you must do thus: First hauing drawen a secret line or thread, from the dif∣ference of the two latitudes, placed according to the rule of greater and lesser before set downe, and marked on both sides of the Instrument: draw another thread, or els lay a ruler so as it may passe thorough the Center, and the line of the wind, or coast wherby the second place bea∣reth

from the first. And wheras those two lines or threds doe touch, make a marke, and then lay a ruler, or extend a thread from the vpper line to the nether line of longi∣tude, so as it may passe hard by the last marke, and then the thread or ruler so laid, will shew you the difference of longitude betwixt the two places. And by this meanes Gemma Frizius sayth, that the Mariners may easilie cor∣rect the longitudes of places as they saile: but how true∣ly, I referre that to the skilfull Pilots.

But for mine owne part, hauing to seeke out in these latter Mappes the way by Sea or Lande to any place I would vse none other Instrument of direction then halfe a Circle deuided with lines like a Mari∣ners Flie, in such sort as you sée in this Figure.