LETTER OF APPOINTMENT by the States General of the Netherlands for Adriaan van Helden as 'military engineer' or 'master of fortifications' (officier der genie), dated June 23rd 1786. 320 x 480 mm. Printed on vellum w. additions in ms. W. red wax seal (dam.). -- Added: Similar letter of appointment for the same as major general of the army ("major generaal over het volk van oorlog"), dated June 8th 1796. 725 x 387 mm. Written on vellum and signed by the president of the 'Nationale Vergaadering' J.A. de Vos van Steenwijk (1746-1813). W. large wax seal of the Batavian Republic. -- (2).