 After 1894, Japan did not employ any foreign military instructor, until 1918 when the country welcomed the fourth French military mission to Japan (1918–19), with the objective of acquiring technologies and techniques in the burgeoning area of military aviation.The French Navy leading engineer Émile Bertin was invited to Japan for four years (from 1886 to 1890) to reinforce the Imperial Japanese Navy, and direct the construction of the arsenals of Kure and Sasebo.For the first time, with French assistance, the Japanese were able to build a full fleet, some of it built in Japan, some of it in France and a few other European nations.