The comments by the directors of the Nautical College in Harlingen on behaviour and level of understanding are categorized. The qualifications vary. For the sake of clarity, the numbers of these qualifications were added. In the case of behaviour, they ranged from lively (‘levendig’ – 1) to troublesome (‘lastig’ – 9). In the case of the level of understanding, qualifications ranged from quick (‘zeer vlug – 1) to difficult in learning (‘moeilijk van begrip’ – 6). As some categories are almost identical, the total number of categories was reduced. The following categories were thus created: Behaviour (B):

• 1. = lively (levendig)

• 2. = orderly (orderlijk)

• 3. = modest and very industrious (bescheiden and zeer vlijtig)

• 4. = modest (bescheiden)

• 5. = fairly modest and fairly industrious (matig bescheiden and matig vlijtig)

• 6. = quiet (stil/bescheiden)

• 7. = becoming (redelijk/betamelijk)

• 8. = slow (traag)

• 9. = troublesome (lastig)

• Level of understanding (LOU):

• 1. = quick (overall term for zeer vlug and vlug)

• 2. = susceptible (vatbaar)

• 3. = reasonably susceptible (redelijk vatbaar)

• 4. = hardly susceptible (nauwelijks vatbaar)

• 5. = slow (overall term for matig vlug and zeer langzaam)

• 6. = difficult in learning (moeilijk van begrip)

The archival record from the Nautical College contains important information about the skills of the students. The three directors of the College frequently checked up on the progress of their pupils. They provided data about the knowledge their pupils had with regard to mathematical and navigational matters. Unfortunately, there is not unequivocal, unambiguous information about the exact content of the courses given by Kallenborn. The content of the courses may be deduced by analysing the progress mentioned in the records. It should noted that the remarks are commensurate with, or at least contain elements equal to, the categories first developed by O.S. Bangma in his capacity as teacher at the Nautical College in Amsterdam. Here again, it should be kept in mind that Pieter Kallenborn was trained by Bangma. In Amsterdam, Bangma introduced five categories, or disciplines, in his courses and all needed to be mastered by the students in order to be eligible to pass the exam for first mate.