A Naval Biographical Dictionary/Denham, Henry Mangles
DENHAM, F.R.S. (Capt., 1846. f-p., 37; h-p., 1.)
Henry Mangles Denham was born 28 Aug. 1800.
This officer entered the Navy, in April, 1809, as a Volunteer, on board the Daphne 20, Capt. Philip Pipon, on the Guernsey and Jersey station; where he next served, from April, 1810, to May, 1814, latterly as Midshipman, in the Vulture 10, Capts. Martin White, Geo. Morris, and Henry Baugh. During the three following years we find him borne on the books of the Queen Charlotte, Boyne, and Prince, ships of the line, but detached the whole of the time on the survey of the Channel Islands, under his former Commander, Capt. Martin White; with whom, as Midshipman and Lieutenant (commission dated 26 Dec. 1822), of the Shamrock 14 he was further employed, from March, 1817, to May, 1827, in examining the English and Irish Channels, and the south-west and north-east coast of Ireland. In Oct. 1827, Mr. Denham assumed command of the Linnet 10, for the purpose of surveying the coast of France; and while nominally attached, between Sept. 1828, and March, 1835, to the St. Vincent, Caledonia, and San Josef, he conducted a survey of the Bristol Channel, and of the ports of Liverpool and Milford. As an especial mark of their approbation of the high merit and talent displayed by Lieut. Denham in the important public services which he had thus performed, the Lords of the Admiralty promoted him to the rank of Commander on the 20th of the month last mentioned. He was subsequently employed, from Jan. 1842, to July, 1845, as Commander of the Lucifer steam-vessel, and of the Royal Sovereign yacht, in defining the coasts of Lancashire and Cumberland. He was then appointed to the Avon steamer; and on 27 Sept. following he sailed on a surveying expedition to the coast of Guinea, including the mouths of the Niger. He returned to England on the attainment of his present rank, 17 Aug. 1846; and since 2 Dec. following has been borne on the books of the William and Mary yacht. Thirty years of Capt. Denham’s servitude in the Navy have been employed in the construction of charts, and eighteen in the actual command of maritime surveys. In 1830 this scientific officer received the thanks and a vote of plate from the Trinity Board; in 1834 he was further presented with the freedom of the borough of Liverpool, and elected a member of the Literary and Philosophical Society at that place; and in 1839 he was chosen a Fellow of the Royal Society; as likewise, in 1841, a Younger Brother of the Trinity Corporation, and a member of the United States’ National Institution for the Advancement of Science. He has received the thanks of the Geological Society, of several Refuge Harbour Committees, and of the Committee at Lloyd’s.
Captain [errata 1] Denham, who married 18 March, 1826, has issue three sons and three daughters.
DENHAM, F.R.S. (Captain, 1846.)
Henry Mangles Denham assisted in surveying the Channel Islands (Guernsey, Jersey, Alderney, &c.). He acted as Chief Assistant in the survey of the English and St. George’s Channels, from the Straits of Dover to the edge of soundings; of the coast of Ireland from the Shannon to Belfast, including Beerhaven, Crookhaven, Valentia, Baltimore, Glandore, Cove of Cork (entrance), Toughall, Waterford, Carlingford, Strangford, Ardglass, Belfast, Copeland Isles, and Larne; and of the English coast, including Falmouth (Sound), Helford, Manacles (reef), St. Helen’s Pool, Scilly Islands, Skerries, Start Bay, Salcombe, Plymouth Sound, and Dartmouth. He has concluded, too, the survey of the Bristol Channel throughout, including Hartland Quay, Clovelly, Barnstaple Bar, Appledore, Ilfracombe, Minehead, Watchet, Bridgewater, Kingroad off the Avon, Cardiff, Newport, Chepstow, Swansea, the Mumbles, Llanelly, Estuary of Bury, Carmarthen, Tenby, Milford Haven, Solvach, St. Bride’s Bay, and Lundy Island; and of the coasts of Lancashire and Cumberland, with the Dee (to Chester), Liverpool Bay, and the Mersey; Morecombe Bay, including Fleetwood, Lancashire, and Piel a Foudra; and the Duddon and Ravenglass estuaries, Whitehaven, Workington, Harrington, Maryport, and Douglas, Isle of Man. The rank of Commander was conferred on him as a reward for the talent he had displayed in the execution of his surveying services generally, and in particular to mark the high sense entertained by the Lords of the Admiralty of the advantages accruing to the public from the completion of his survey of the port and harbour of Liverpool and the neighbouring coast. The return of the port of Liverpool to the mere capacity of a half-tide harbour Capt. Denham succeeded in averting by harrowing a new opening through the Burbo and Jordan Sands, which, on the accession of Her Majesty to the throne, was named the “Victoria Channel.” In reference to a steam survey made by him in the North Sea, the present Hydrographer of the Admiralty, Sir Fras. Beaufort, declared it to be his conviction “that no man would have achieved that great work with more skill;” and, in remarking upon the survey of Morecombe Bay, the same eminent authority recorded it as his opinion “that a more complete and masterly work had rarely been sent to the Admiralty Office.” In allusion to Capt. Denham’s services in the Avon, on the coast of Africa, whither he had been sent for the express purpose of surveying the Bight of Benin, the Hydrographer thus expresses himself: “In examining a survey made in such a deleterious climate, along such an impracticable coast, and in contact with such a treacherous population, I was prepared to make great allowances for work done under such striking disadvantages; but I find, with equal pleasure and surprise, that the whole has been performed with all the precision and fulness that could have been expected if made under the most favourable circumstances.” For this service Capt. Denham was promoted to Post-rank. Subsequently to his return to England he executed several commissions with reference to the steam marine from the Lords Committee of the Privy Council for Trade, under the conjoint authority of the Board of Admiralty, and also with reference to harbour improvements at Swansea and Bideford. His name continued, as a Supernumerary, on the books of the William and Mary yacht, until the summer of 1847. Capt. Denham has been appointed Inspector of Steam-boat Accidents. He is the inventor of “Denham’s Rowlocks” for rowing boats; and of “Denham’s (registered) Jury-Tiller” for steering a ship on fire abaft, or when twisting her rudder-head, breaking her tiller in a gale of wind, or receiving the enemy’s shot.