theater of operations. The Brazilian Armada had a total of 59 vessels of various types in 1851: 36 armed sailing ships, 10 armed steamships, seven unarmed sailing ships and six sailing transports. More than a decade later the Armada was once again modernized and its fleet of old sailing ships was converted to a fleet of 40 steamships armed with more than 250 cannons. In 1864 the navy fought in the Uruguayan War and immediately afterwards in the Paraguayan War where it annihilated the Paraguayan navy in the Battle of Riachuelo. The navy was further augmented with the acquisition of 20 ironclads and six fluvial monitors. At least 9,177 navy personnel fought in the five years' conflict. Brazilian naval constructors such as Napoleão Level, Trajano de Carvalho and João Cândido Brasil planned new concepts for warships that allowed the country's Arsenals to retain their competitiveness with other nations. All damage suffered by ships was repaired and various improvements were made to the ships. In 1870, Brazil had 94 modern warships and had the fifth most powerful navy in the world. Final years, 1870–89 During the 1870s, the Brazilian Government strengthened the navy as the possibility of a war against Argentina over Paraguay's future became quite real. Thus, it acquired a gunboat and a corvette in 1873; an ironclad and a monitor in 1874; and immediately afterwards two cruisers and another monitor. The improvement of the Armada continued during the 1880s. The Arsenals of the Navy in the provinces of Rio de Janeiro, Bahia, Pernambuco, Pará and Mato Grosso continued to build dozens of warships. Also, four torpedo boats were purchased. On 30 November 1883, the Practical School of Torpedoes was created along with a workshop devoted to constructing and repairing torpedoes and electric devices in the Arsenal of Navy of Rio de Janeiro. This Arsenal constructed four steam gunboats and one schooner, all with iron and steel hulls (the first of these categories constructed in the country). The Imperial Armada reached its apex with the incorporation of the ironclad battleships Riachuelo and Aquidabã (both equipped with torpedo launchers) in 1884 and 1885, respectively. Both ships (considered state-of-the-art by experts from Europe) allowed the Brazilian Armada to retain its position as one of the most powerful naval forces. By 1889, the navy had 60 warships and was the fifth or sixth most powerful navy in the world. In the last cabinet