(Covers to) Extension of the triangulation of the Ordnance Survey into France and Belgium :with the measurement of an Arc of parallel in latitude 52(degree) N. from Valentia in Ireland to Mount Kemmel in Belgium. Published by order of the right Hon. Sir George C, Lewis, Bart. Secretary of State for war. By Colonel Sir Henry James, R.E., F.R.s., &c. Director of the Ordnance Survey. London : Printed by George Edward Eyre and William Spottiswoode, Printed to the Queen's most excellent Majesty. for the Majesty's Stationary Office. 1863.

Printed in vi, 62 pages, with 7 plates. Includes table of contents, text, and manuscript letters and notes. Accompanied by 21+2 pages of text, note and figure, titled: Sur l'Influence des attractions locales dans les Operations Geodesiques ... Par Le General de l'Infantierie T.F. de Schubert ... Altona, 1860. Bound in light brown leather covers, with "Extension of the triangulation of the Ordnance Survey into France and Belgium" and a decorative border stamped in gilt. Noted in introduction: "All computations here given have, been made by or under the immediate superintendence of Captain alexander Ross Clarke, R.E."