In the late Tang dynasty, people mining saltpeter for gunpowder discovered that when saltpeter dissolved in water, it absorbed a great deal of heat, lowering the water's temperature until it froze. From then on, there was a way to make ice in summer, and merchants added sugar to ice to attract customers.
People assumed seawater would not freeze, yet rivers did—and the Seine froze as well. From the latter half of the sixteenth century onward, Europe entered the "Little Ice Age," and even Louis XIV's wine in the Palace of Versailles froze.
In coastal waters, where the water was shallower, seawater could freeze rapidly when temperatures dropped sharply, such as during a severe cold wave. Once sea ice formed, soluble salts were expelled during the crystallization process, causing the salinity of the unfrozen seawater to rise rapidly. Its density increased, its freezing point dropped, and if The Waves churned it at that time, an "ice-water mixture" would appear.
Saltpeter could not only be used to make gunpowder and fire cannonballs from cannons; it could also serve the purposes of war this way. So long as British Navy warships were trapped by the coast, naval officers deprived of mobility could only disembark and surrender to the French Army, who came riding over the ice on horseback.
The forces of nature were beyond human control. Humans themselves were part of nature, coexisting with all manner of living things upon the land and amid the climate. Human activity brought both destruction and construction. Lannes was sent to Antwerp to build defensive works, and the first task was to construct embankments near the mouth of the Scheldt River so that the deep-draft British Navy warships could not enter the inland waterways.
Generally speaking, the deeper a ship's draft, the greater its carrying capacity. Those