In the chambers, the powder was deposited in three nearly equal quantities; it was done up in fifty-pound bags, and the proportion in each chamber was contained in a wooden case, nearly as large as the chamber itself. Ignition was communicated by means of a voltaic battery; the conducting wires, one thousand feet in length, were passed over the cliff, one to each chamber, and the electricity was communicated in a shed built for the purpose on the top of the cliff, about fifty yards from the edge. The explosion was conducted by Lieutenant Hutchinson, R.E., who was engaged with General Pasley in blowing up the wreck of the Royal George. The time appointed for the explosion to take place, was two o’clock P.M., 26th January, 1843, the tide being then at its lowest ebb. The arrangements, to preserve order and prevent danger, were good. A space was kept clear by a cordon of artillery, and the following programme was issued:-- “Signals, January 26, 1843. “1st. Fifteen minutes before firing, all the signal flags will be hoisted. “2nd. Five minutes before firing, one gun will be fired, and all the flags will be hauled down. “3rd. One minute before firing, two guns will be fired, and all the flags (except that on the point which is to be blasted) will be hoisted up again.” These signals were given exactly at the specified times, and when the expected moment arrived, a deep subterranean sound was heard, a violent commotion was seen at the base of the cliff, and the whole mass slid majestically down, forming an immense _débris_ at the bottom. Tremendous cheers followed the blast, and a royal salute was fired. The remarks of different intelligent observers, as to the effects of this explosion, would of course differ according to their position with respect to the scene of explosion. One observer states that “the earth trembled to the distance of half a mile; a stifled report, not loud, but deep, was heard; the _base_ of the cliff, extending on either hand to upwards of five hundred feet, was shot as from a cannon, from under the superincumbent mass of chalk seaward; and in a few seconds not less than a million tons of chalk were dislodged by the shock, and settled gently down into the sea below.” But the most eminent observer who has described the effects of this explosion is Sir John Herschel, from whose letter to the _Athenæum_ we gather the following particulars. His position was on the summit of the cliff, next adjoining the scene of operations, to the southward, the nearest point to which access was permitted.