The accidental destruction of the three smaller chambers was providential, for had they exploded, the battery-shed, with Captain Frome and his assistant, would inevitably have been carried away, and crushed among the falling masses: as it was “the electricity of the two Grove’s batteries, on igniting the powder in the larger chambers, caused an instantaneous disconnection of the Smee’s battery from the smaller chambers, and, at the same time, the table on which they stood was jerked violently forward between two and three feet, upsetting the Smee’s battery on the floor, and throwing out from the others also a quantity of the acids.”—‘Illust. Lond. News,’ September 28, 1850. Footnote 49: ‘Professional Papers,’ i., N. S., 68-86. Colonel Lewis’s Paper in ‘Jones’s Journal,’ November, 1850. Footnote 50: Now a quartermaster-sergeant. In his early career he was employed in the chronometrical determination of the longitude of Valentia, and for many years rendered very useful services in filling in the railways on the one-inch map. His talents and energy have singled him out at different times for the execution of particular duties. He was intrusted with the local superintendence of the survey, &c., of Her Majesty’s domain at Osborne, in the Isle of Wight; and as a mark of approbation for the “attention and care” he exercised in discharging the duty, His Royal Highness Prince Albert presented him with a cheque for ten pounds. He also had subordinate charge of the survey made for the military encampment at Chobham Common. Footnote 51: ‘Professional Papers, R. E.,’ iii., N. S., p. xxiii. Footnote 52: Captain Yolland, ‘Sector Volume,’ p. xiii. Footnote 53: Private B. K. Spencer took a few observations at these stations. Footnote 54: A few observations were taken at this station by Corporal Jenkins. Footnote 55: Captain Yolland, ‘Sector Volume,’ xiii. Footnote 56: Ibid., xiv. Footnote 57: On journeying from Roach, in Cornwall, to Exeter, he sat by the side of the Astronomer Royal, who made various inquiries concerning the survey. At length, he asked, “What _instrument_ have _you_ been using?” “Professor Airy’s zenith sector,” was the reply. “Indeed, _I_ am Professor Airy!” The surprise and pleasure of the sergeant, before unconscious of the presence of the eminent astronomer, may be left to the imagination of the reader to conceive. The incident is memorable, on account of the introduction, thus singularly obtained by sergeant Steel, and of the information he received from the Professor in the efficient use of the instrument, as well as in some salient points connected with astronomy. Footnote 58: Captain Yolland’s ‘Sector Volume,’ pp. xi. xii. Footnote 59: