11818. Risālah fī al-burhān ʻalá ittikhādh al-muqaddimat allatī ahmalahā Arshimīdis fī tasbīʻ al-dāʼirah wa-kaifīyah dhalika. [Transcribed from MS. Thurston 3, f. 128v l. i - f. 129r l. ix.]
11819. Risālah fī al-dawāʼir allatī taḥuddu al-sāʻāt al-zamānīyah. [Transcribed from MS. Thurston 3, f. 126v l. xviii - f. 128r l. xxii.]