These and other ideas were successfully experimented with by Captain Sir Charles Douglas in the late I 770s and early I 780s.
ezi nezinye izimvo zazinempumelelo zifuniselwe ngumphathi umnu Charlie Douglas kamva ngowewaka linamakhulu asixhenxe anamashumi asixhenxe naphambili kwiwaka linamakhulu asixhenxe anesibhozo.