risk of the line breaking, because the velocity of a rocket increases gradually, whereas that of a shot fired from a mortar was so great and sudden that the line was frequently broken; the whole of Trengrouse's apparatus could, moreover, be packed in a chest four feet three inches by one foot six inches, and carried by vessels of every size, while Manby contemplated the use of the mortar only on shore, and the safety of the vessel depended therefore on the presence of an apparatus in the vicinity of the wreck (Trans. Soc. of Arts, xxxviii. 161–5).
It was not, however, until 28 Feb. 1818, after many journeys to London, that Trengrouse exhibited his apparatus before Admiral Sir Charles Rowley [q. v.] A committee was appointed, and on 5 March it reported ‘that Mr. Trengrouse's mode appears to be the best that has been suggested for the purpose of saving lives from shipwreck by gaining a communication with the shore; and, so far as the experiments went, it most perfectly answered what was proposed;’ it was also suggested that a specimen apparatus should be placed in every dockyard that naval officers might become familiar with its working (Parl. Papers, 1825, xxxi. 361). In the same year a committee of the elder brethren of Trinity House also reported in its favour, and recommended that ‘no vessel should be without it.’ The government ordered twenty sets, but afterwards preferred to have them constructed by the ordnance department, and paid Trengrouse 50l. compensation. In 1821 the Society of Arts awarded him their large silver medal and thirty guineas for the invention. Alexander I of Russia also wrote Trengrouse an autograph letter, presented him with a diamond ring in recognition of the usefulness of his apparatus, and invited him to Russia; but apart from the prize awarded by the Society of Arts and the compensation paid by the government, Trengrouse reaped no pecuniary reward from his invention. An improved rocket was invented by John Dennett [q. v.] in 1826; the one now in use was devised by Colonel Boxer in 1855. The rocket has completely superseded the mortar, and is now, next to the lifeboat, the most important means of saving lives from shipwrecks. Since 1881 nearly five thousand lives have been saved in this way (Tables relating to Life Salvage, 1897).
Trengrouse died at Helston on 14 Feb. 1854; by his wife Mary, daughter of Samuel Jenken, he left issue three sons and five daughters. His widow (b. 9 Sept. 1772) died at Helston on 27 March 1863.
[Authorities cited; Gent. Mag. 1819 i. 559–60, 1822 ii. 71; Encycl. Britannica, 9th ed. xi. 143; Illustr. London News, 23 Oct. 1854; Boase and Courtney's Bibl. Cornub.; Boase's Collect. Cornub.; private information.]
TRESHAM, FRANCIS (1567?–1605), betrayer of the ‘gunpowder plot,’ born about 1567, was the eldest son of Sir Thomas Tresham (1543?–1605) by his wife Muriel, daughter of Sir Robert Throckmorton of Coughton, Warwickshire [see under Tresham, Sir Thomas, d. 1559]. According to Wood (Athenæ Oxon. i. 754), Francis was educated ‘either in St. John's College or Gloucester Hall, or both,’ but his name does not appear in the university registers, and the religion of his father and himself would in any case have prevented his graduating. As early as 1586 he is mentioned as frequenting the French ambassador's house with Lady Strange, Lady Compton, and other Roman catholics. He was ‘a wylde and unstayed man,’ and in 1596 he is said by Father Gerard to have been arrested with Catesby and the two Wrights, during Elizabeth's illness, to prevent them causing any disturbance in case of her death. In 1600–1 he became involved in Essex's rebellious schemes, to the disgust of his jesuit advisers, one of whom declared that if Tresham ‘had had so much witt and discretion as he might have had, he would never have associated himself amongest such a dampnable crewe of heritikes and athistes’ (Hist. MSS. Comm. 12th Rep. pt. iv. pp. 369–70). He was one of those left by Essex to guard Lord-keeper Egerton in Essex House on Sunday, 8 Feb. 1600–1, and refused to allow Egerton either to leave or to communicate with the queen. He was imprisoned first in the White Lion, Southwark, and then in the Tower. His father, Sir Thomas Tresham, bought his pardon at the price of three thousand marks; he was also required to give satisfaction, probably of a monetary kind, to Egerton and the lieutenant of the Tower, his delay in so doing retarding his release until 21 June (Salisbury to Windebank, Cal. State Papers, Dom. 1601–3, p. 205; three letters relating to his release and the losses entailed upon his father among the Tresham papers at Rushton are described as ‘curious’ and ‘interesting,’ Cal. Rushton Papers).
Tresham seems to have lived a dissatisfied and not very creditable life. His father allowed him the use of his manor of ‘Hoggesdon’ (? Hoxton), but Francis was not above entering into a conspiracy with one of his father's servants to deceive him about the extent of some lands they were to exchange (Cal. Rushton Papers, p. 11), and there are
