Much of the expense of the service was paid by Mr. Catt, jun., a miller, to whom the surrounding property belonged, and who, as well for his own interest as for the welfare of Newhaven and its harbour, undertook a large share in the liability. The total cost of the work was 907_l._ 12_s._ 11½_d._ Of this sum only 92_l._ 3_s._ 1_d._ was spent on sapper labour, which included their services for levelling the ground, and other preliminary duties, excavating the galleries, shafts, and chambers, digging a trench above the cliff, loading and tamping the mines, making surveys and sections of the cliff and the works, preparing and laying wires, clearing away the debris, and various other miscellaneous duties, which the extensive and peculiar character of the operations rendered essential. Lieutenant-General Sir John Burgoyne, the inspector-general of fortifications, Lieutenant-General Sir Charles Pasley, and a number of officers of royal engineers, were present to witness the explosion. Later in the day the non-commissioned officers and privates commemorated the success of their exertions with an excellent dinner. “Night and day,” wrote Colonel Lewis, “the detachment worked with great zeal and alacrity, exposed to colds from draughts and alternations of temperature, and to injury from falling masses. Nevertheless, no material accident occurred to any one, and all gained the praise of their officers, and the respect of the inhabitants of Seaford for their courteous behaviour and good conduct.”[49] The observations made with Airy’s zenith sector for the determination of the latitudes of various trigonometrical stations used in the ordnance survey of the British Isles, which commenced in 1842, terminated in December 1850, and the results have become the subject of an important volume from the pen of Captain Yolland, R.E. The instrument at first was in charge of officers of the corps, but in course of time, from a paucity in their number, it devolved upon corporal, afterwards sergeant, James Steel. The first man of the sappers honoured with the use of the instrument was private Benjamin Keen Spencer,[50] who was employed with the earliest parties in carrying on the observations; and it is not a little curious to add, that General Colby directed his own personal observations, the work of his most able days to be tested by sergeant Steel. This is a striking proof both of the greatness of his mind, and his freedom from those petty jealousies which sometimes mar the superiority of distinguished characters.[51]