that winds forced it to sail on a southeast-by-east course (SEbE, "Quarto di Scirocco verso Levante"). Southeast-by-east is three quarter winds (or 33.75°) away from east (on a 32-point compass, in order of quarter-winds away from east, 1 quarter is east-by-south, 2 quarters is East-southeast, 3 quarters is southeast-by-east). That means that the navigator should consult the third row, q = 3, on the toleta. Suppose the ship sailed 100 miles on the SE-by-E bearing. To check his distance from the intended eastward course, the mariner will read the corresponding entry on the alargar column and immediately see he is 55 miles away from the intended course. The avanzar column informs him that having sailed 100 miles on the current SEbE course, he has covered 83 miles of the intended E course. The next step is to determine how to return to the intended course. Continuing the example, to get back to the intended Eastward course, our mariner has to re-orient the ship's bearing in a northeasterly direction. But there are various northeasterly angles – NbE, NNE, NE, ENE, etc. The mariner has a choose the bearing – if he returns by a sharp angle (e.g. North by east), he will return to the intended course faster than at a more gentle gradient (e.g. East by north). Whichever angle he chooses, he must deduce exactly how long he must sail on that bearing in order to reach his old course. If he sails too long, he risks overshooting it. Calculating the return course is what the last three columns of the toleta are for. In the fourth column, the return angles are expressed as quarters from the intended course bearing (not the current course bearing). In our example, the mariner intended to go east, but has been sailing southeast-by-east for 100 miles. Given the winds, he decides it is best to return to the original course by re-orienting the ship east-northeast (ENE, "Greco-Levante"). ENE is two quarter-winds above the intended bearing, East, so now he looks at second row ("quarters = 2") on the fourth column of the table. The fifth column is the ritorno, the distance he must travel on the chosen return angle to recover the original course. Given he has chosen to return by ENE bearing (q = 2), then he must read the second row of the ritorno column, which shows the number 26. This represents