I am going back over the Staat van Orlog te Water for the year 1629. The Rotterdam ships (it calls the admiralty the Admiraliteit tot Rotterdam, not the Admiraliteit van de Maze). This list does not give dimensions, only the size in lasts. My theory is that the last measurements of Rotterdam ships is based on the dimensions in Maas feet (about 308mm), not Amsterdam feet (283mm). The basis for my theory is a list of Rotterdam ships from 1642. I have dimensions for most of those ships and can tell how the last figures were calculated. The small frigates Utrecht, Overijssel, and Gelderland are all listed as being of 90 lasts. Their dimensions in Maas feet are
100ft x 23ft x 8ft
. The calculation then is
90 = 100 x 23 x 8 / 207
. The usual way is round to the closest ten lasts. Of course, we are used to dimensions written in Amsterdam feet. The dimensions in Amsterdam feet are
109ft x 25ft x 8ft-8in
. The size in lasts, calculated from Amsterdam feet is
120 lasts = 109ft x 25ft x 8.727273/207
. You can see that the size in what I call "Amsterdam lasts" is about 1.3 times greater than the size in "Rotterdam lasts".
