Stockholm, home to the author and also known as "Beauty on the Sea", has much to offer, including a rare insight into ship construction and architecture in the early seventeenth century. Sweden was busy building an empire around the Baltic Sea in northern Europe and a strong navy was essential. During the I620s Sweden was at war with Poland, and in 1625 the Swedish king Gustavus Adolphus ordered new warships, among them the Vasa. The Vasa was built at the Stockholm shipyard by Henrik Hybertsson-an experi­ enced Dutch shipbuilder. In the seventeenth century, however, architectural draw­ ings and engineering specifications did not exist. Instead of using calculations, shipbuilders used so-called reckoning, which recorded certain ship measurements. The reckoning used in building the Vasa were intended for smaller ships with only one gun deck. The Vasa was built quite differently. When in 1628, in the presence of spectators among them foreign diplomats, the Vasa heeled over and sank on its maiden voyage, the experience of the master builder and the skills of the carpenters he employed were not much above what we today would call the component level of the time.The knowledge ofbuoyancy, bal­ last, centerofgravity and stability was basic at best.