Collection Manuscript/Mixed Material Image 1 of Item 31. Letter from the Pengeran of Siak Indrapura to Colonel William Farquhar. Resident of Singapore. 5 Muharram 1237 (2 October 1821). Item 31. Letter from the Pengeran of Siak Indrapura to Colonel William Farquhar. Resident of Singapore. 5 Muharram 1237 (2 October 1821).