Dee ihe na-aga n'ihu maka paragraf a - N'afọ 1801, Camille Alphonse Trezel banyere dị ka onye na-ese ihe n'ọfịs agha ma n'afọ 1803 ọ ruru ọkwa lieutenant na ngalaba nke ndị injinia topographical. E zigara ya na 1804 na ndị agha nke Holland, a kwalitere ya n'afọ na-esote onye enyemaka injinia geographer. Mgbe agha Poland gasịrị
, a họpụtara ya ka ọ bụrụ onye enyemaka nke General Gardane na French embassy na Persia na 1807-1808, mgbe ahụ onye enyemaka nke General Armand Charles Guilleminot na nloghachi ya na 1809. Ọ bụ odeakwụkwọ nke Kọmitii na Delimitation nke Illyria, e buliri ya n'ọkwá onye isi (1810), ma zigara ya ndị agha Spain. A kpọghachiri ya na Germany na ngwụcha afọ 1811, ọ rụrụ ọrụ na ngalaba nyocha nke Hanseatic, na mkpọsa na Rome, ghọrọ onye isi ndị ọchịagha (1813), Onye isi ndị ọrụ nke 13th Division, ma rụọ ọrụ na nchekwa nke Mainz.