Edmund Tolson Wedmore

“ Joly made considerable additions, including an appendix of 114 pages; the first volume of the new edition was published in 1899, and the second in 1901. While occupied with this work, Joly communicated several memoirs to the Royal Irish Academy: 'Astatics and quaternion functions,' 'Properties of the general congruency of curves,' and 'Some applications of Hamilton's operator in the calculus of variations' were all read in 1899; in the first, quaternions are applied to the geometry of forces, in the second to pure geometry, and in the third to some of the equations of mathematical physics. ”

“ The properties of linear vector functions were further studied in 'Scalar invariants of two linear vector functions' (Trans. R.I.A. 1896, xxx. 709) and 'Quaternion invariants of linear vector functions' (Proc. R.I.A. 1896, iv. 1) , while the extension of the quaternion calculus to space of more than three dimensions was discussed in 'The associative algebra applicable to hyperspace' (Proc. R.I.A. 1897, v. 75) ; the algebras considered are those that are associative and distributive, and whose units satisfy equations of the same type as the units of quaternions. ”

“ He also edited Preston's 'Theory of Light' (3rd edit. 1901) . He was elected F.R.S. in 1904, and was a trustee of the National Library of Ireland and president of the International Association for Promoting the Study of Quaternions. ”