pre-dreadnought battleships, the of 1907. Coal was the almost exclusive fuel for the pre-dreadnought period, though navies made the first experiments with oil propulsion in the late 1890s. An extra knot or two of speed could be gained by applying a 'forced draught' to the furnaces, where air was pumped into the furnaces, but this risked damage to the boilers. Pre-dreadnought fleets and battles The pre-dreadnought battleship in its heyday was the core of a very diverse navy. Many older ironclads were still in service. Battleships served alongside cruisers of many descriptions: modern armoured cruisers which were essentially cut-down battleships, lighter protected cruisers, and even older unarmoured cruisers, sloops and frigates whether built out of steel, iron or wood. The battleships were threatened by torpedo boats; it was during the pre-dreadnought era that the first destroyers were constructed to deal with the torpedo-boat threat, though at the same time the first effective submarines were being constructed. The pre-dreadnought age saw the beginning of the end of the 19th century naval balance of power in which France and Russia vied for competition against the massive Royal Navy, and saw the start of the rise of the 'new naval powers' of Germany, Japan and the United States. The new ships of the Imperial Japanese Navy and to a lesser extent the U.S. Navy supported those powers' colonial expansion. While pre-dreadnoughts were adopted worldwide, there were no clashes between pre-dreadnought battleships until the very end of their period of dominance. The First Sino-Japanese War in 1894–95 influenced pre-dreadnought development, but this had been a clash between Chinese battleships and a Japanese fleet consisting of mostly cruisers. The Spanish–American War of 1898 was also a mismatch, with the American pre-dreadnought fleet engaging Spanish shore batteries at San Juan and then a Spanish squadron of armoured cruisers and destroyers at the Battle of Santiago de Cuba. Not until the Russo-Japanese War of 1904–05 did pre-dreadnoughts engage on an equal footing. This happened in three battles: the Russian tactical victory during the Battle of Port Arthur on 8–9 February 1904, the indecisive Battle of the Yellow Sea on 10 August 1904, and the decisive Japanese victory at the Battle of Tsushima on 27 May 1905. These battles upended prevailing theories of how naval battles would be fought, as the fleets began firing at one another at much greater distances than before; naval architects realized that plunging