Manuscript, 'On the velocity of transmission through sea-water of disturbances of large amplitude caused by explosions' by Richard Threlfall and John Frederick Adair The authors write: 'During the latter months of the year 1886 and the first half of the year 1887, experiments were undertaken by one of us in conjunction with Lieutenant Ottley, R.N., of Her Majesty’s ship “Nelson”, then stationed at Sydney, with the view of obtaining definite information as to the existence or non-existence of the supposed phenomenon of “explosion by influence.” It had been previously discovered (Threlfall, ‘Phil. Mag.,’ March, 1886) that in the case of small explosions of fulminate of mercury under water, there was a sort of directed effect due to want of symmetry in the disposition of obstacles surrounding the centre of explosion.' Annotations in pencil and ink. Includes two sample prints of a chronograph plate, a plan diagram of experimental apparatus and a 'sketch shewing method for finding the distance EF between two spikes in the tops of two piles in Berry's Bay, Port Jackson'. Subject: Physics Received 14 March 1889. Read 21 March 1889. Communicated by Joseph John Thomson. A version of this paper was published in volume 46 of the Proceedings of the Royal Society as 'On the velocity of transmission through sea-water of disturbances of large amplitude caused by explosions'. 1889