On the arithemetic of impossible quantities. On the causes which affect the accuracy of barometrical measurements. Remarks on the astronomy of the Brahmins. On the origin and investigation of porisms. Observations on the trigonometrical tables of the Brahmins. Theorems relating to the figure of the earth. On the solids of greatest attraction. On the progress of heat in spherical bodies. Account of a lithological survey of Schehallien. On the naval tactics of the late John Clerk