Collection Manuscript/Mixed Material Image 1 of Item 4. Letter from Tengku Pengeran from Siak to Colonel William Farquhar. Resident of Singapore. 11 Rejab 1234 (6 May 1819). Item 4. Letter from Tengku Pengeran from Siak to Colonel William Farquhar. Resident of Singapore. 11 Rejab 1234 (6 May 1819).