"And in his Letter to Baron Wasenberg, Envoy from the King of Sweden, dated the 22d of April 1743... he says, "that every Swedish Man of War, and Hospital Ship, was last Year furnished with one of my Engines; which had not been done, in case so they had not experienced the Benefit of the same, the Campaign so before that." So that a Trial was made with these Ventilators in the Year 1741, which proved a very sickly Summer in the Swedish Fleet, except only in the Ship or Ships, which were refreshed by Ventilators: A strong Instance of their great Usefulness; which induced the Swedes to put them into every Man of War and Hospital-Ship, the rear following."