'T Derde deel van 't Licht der zee-vaert, inhoudende de beschryvinghe der zeecusten van de Middelandtsche...

long cross, and A B, the bottom edge of the ear on the small cross-piece, as in figure N. 2, and place that on the staff from point D at the slanted slider inward towards C. On that point draw a small transverse line; from there one must begin the marking. Take the width between the center line of the staff and the bottom edge of the ear that is on the top cross-piece, as in the aforementioned figure N. 2, from F to A; place that on the quadrant from A towards F at H, and from C towards G at I, and draw the line H I. Note then how all the lines coming from A, the center of the quadrant, intersect this line H I: just so must the staff (beginning from point C with 90, 80, 70, &c.) be marked. But if, by doing so, one could not obtain as many degrees on the staff as one desired for use, then set the top small cross-piece a third or fourth part lower on the large cross as you prefer, so that the bottom edge of the ear A B (in figure N. 2) comes to stand at M N. Take then, in place of F A, the length F M, and place that on the quadrant from A towards F at K, and from C in L, and draw the line K L. That is then also (through the cutting of the lines coming from the center through the divisions of the quadrant) marked appropriately. But one must make a certain mark on the long cross, in order to set that small cross-piece exactly as one would wish to use these second markings. If one wishes to make even more markings on the same staff, one shifts that top small cross-piece further downward and does as aforementioned, but one must not forget each time to make certain marks on the long cross to set the small cross-piece well according to the marking one desires to use.

To mark this graedbooghe quadrant/degree-arc more perfectly from tables, draw on a smooth board covered with paper a straight line, as long or longer than the staff one desires to mark. With the compass, take thereafter the width between the center line of the staff and the bottom edge of the ear on the small cross-piece (as in figure N. 2, F A or F M or also F O, whatever marking one desires to make) and set that taken width as many times along the aforementioned line as one can, and divide each of those lengths into 10,000 parts. The table alongside shows how many of those parts one should mark off on the staff for each degree or quarter of a degree, beginning (as in the aforementioned figure N. 2) from point C. The first column of the table shows the degrees, the second the minutes, the third the parts that one must take for the degrees and minutes alongside it, as for example: For the first half-degree or 30 minutes, 87; for one degree, 175; for 2 degrees and 15 minutes, 393; but for 6 degrees and 45 minutes, 1184 parts. If one could not divide a short width like F M or F O into 10,000 parts, one may divide it into half as many parts, and take against that again half as many small parts for each degree or its portion. If one cannot do that either, one divides into 1,000 parts, then also leaving out a digit from the numbers in the table each time, as where one would take 175 for the first degree, one takes 17, and so as one can, even a half; for the eighth degree, in place of 1405, one takes 140, and so forth.

Lastly, draw two parallel lines on the slanted slider, standing at the outer end of