The great clock-spring, once wound, drives the mechanism until the energy is spent. The steam furnace produces power without limit of spring — but at the cost of smoke, weight, and theological controversy. Each mechanism chosen here carries its own weight, its own cost, and its own range. The choice of motive power is the choice of what kind of enterprise this will be. Choose as though the horizon you name is the horizon you must actually reach.

The provisions aboard are the character of the vessel made manifest. The rose and the chalice, the chapel and the gaming table — each signals something to those who come aboard, and something to those who commission you. Leonardo observed that the structure of a plant — its root depth, its branching, its relationship to what sustains it — reveals the conditions under which it was grown. The provisions you select reveal the same.

The navigator's instruments determine what can be reached and what cannot. The compass rose measures bearing. The dividers measure distance. The gradatum measures angle of ascent and descent. Before selecting the cities of your itinerary, confirm that your motive power can carry you between them — not in theory, but at the range stated in your design. A route that cannot be completed is not a route. It is a failure waiting to be timed.