Collection Manuscript/Mixed Material Image 1 of Item 39. Letter from Sultan Ahmad ibn Sultan Zainal Abidin of Terengganu to Colonel William Farquhar. Resident of Singapore. 5 Syaaban 1237 (27 April 1822). Item 39. Letter from Sultan Ahmad ibn Sultan Zainal Abidin of Terengganu to Colonel William Farquhar. Resident of Singapore. 5 Syaaban 1237 (27 April 1822).