The small frigates Utrecht and Overijssel

The list that I just received, dating from 1642, is quite interesting. That list confirms what I had already seen. The small Rotterdam frigates Utrecht and Overijssel were built in 1636, not in 1638, as is stated in Vreugdenhil's list. The 1642 list also gives their size as 90 lasts. I suspect that figure is calculated from their size in Maas feet (308mm), not from the size in Amsterdam feet (283mm). The dimensions of the Utrecht and Overijssel, in Maas feet, are 100ft x 23ft x 8ft. If we look at the equation for lasts, we see 90 lasts = (100 x 23 x 8) / K. We solve for K = (100 x 23 x 8)/90. That gives a K=204.44, which is very plausible. I predict that if we converted the dimensions to Amsterdam feet, we would see a K that is too large. As for the 130 last ships (dimensions in Maas feet of 106ft x 25ft x 9.5 or 10ft), we see 130 lasts = (106ft x 25ft x 10ft)/K. We solve for K=(106 X 25 x 10)/130. That gives us a K=203.846, which is a very plausible figure.