Thames Tunnel (continued)
January 4, 1827. —A work that requires such close attention, so much ingenuity, and carried on day and night by the rudest hands possible—what anxiety, what fatigue, both of mind and body! Every morning I say, Another day of danger over! [marginal notes: Observations on the responsibility attached to this enterprise.]
January 12.—It is astonishing how the silt resists the sliding of the top staves. Assured as we were of having stiff clay from 33 to 37 feet, with what confidence we might have looked to making 18 feet per week. There would be no difficulty in having accomplished it. We must not look back, but overcome all difficulties!
January 16.—Isambard having been up several successive nights, went to bed at ten, and slept till six the next morning. I am very much concerned at his being so unmindful of his health. He may pay dear for it. [marginal notes: Isambard on duty several successive nights.]
February 2.—Work done to this day 405 feet 4 inches.
February 3.—I visited the works; and, being in the cabin, I complained of the dust there. Dust under the Thames!
February 26.—I went to the Tunnel. The arch being well lighted up, and the whole walk completed, a few visitors were admitted. The coup d’œil was splendid. Mrs. Brunel, Emma, Sophia and her three little children were the first. It gave me great pleasure to see the whole of my family in the new scene.
March 21.—There being no clay above us, there is much to apprehend from the springs. It would be much better to work slower than we do. It is indeed very hard to be under the necessity of driving. Anxiety increasing daily. [marginal notes: No clay above head; should work slower.]
March 28.—The top pumps failed; the water rose above the abutting screws. The frames of some of them could not be advanced, nor could the bottom brickwork be laid down—great source of complaint. Isambard called the men in at 10 o’clock; they went on cheerfully. It is surprising that the men are so steady. [marginal notes: Water increasing daily.]
March 29.—Things are getting worse every day by the influx of water; by which the ground is softened, and the operation rendered extremely complicated and slow. As to the ground, it is evident we are now as Isambard found it by his borings of August last. We have nothing above our heads but clayey silt, and it is of a nature to be detached and run into mud by the action of water. [marginal notes: Our situation is getting much worse daily.]
April 3.—The pumping now requires forty hands. There is no exaggeration in saying that the influx of water, and the badness of the ground, cause an extra expense of 150l. a week.
April 7.—It may now be said that we are contending with the elements above and around, gaining and disputing every inch that we add to the structure. [marginal notes: Obstacles in every way.]
April 9.—Isambard’s birthday, he being of age to-day.
April 14.—Doing as well as can be expected from the nature of the ground, and the difficulties that increase upon us.
April 18.—The faces are found extremely tender; but having proceeded with great caution, no accident occurred. None, I feel confident, would occur if all idea of piece-work were abandoned. It always operates as a stimulant, a very dangerous one. Obliged to drive on, on account of expense, we run imminent risks indeed for it. That a work of this nature, under such circumstances, should be thus carried on, is truly lamentable. It is obvious that the clay we have above our heads has been broken, by the ground beneath it running or breaking in upon us. We shall have to fight it out until we have a stronger or thicker stratum of clay. Sad prospect indeed it is for us! [marginal notes: To be obliged to drive too fast is a sad alternative.]
April 20.—The ground at No. 1 broke in again, and occasioned great delay. Some bones and china came down.
April 22.—The diving-bell being on the spot, and Isambard having moored it over the shield, he and Gravatt  descended at thirty feet water. They found the same substances which had come through the ground into the Tunnel. When Isambard was in the bell, he drove a strong rod into the ground. Nelson, who was in the frame, heard the blows.
April 29.—Ground improving as we advance; we are not, however, free from danger: a dreadful alarm took place this morning. While Isambard and Gravatt were at breakfast, the porter came running in, and exclaiming, ‘It is all over! The Tunnel has fallen in, and one man only has escaped.’ Gravatt was the first to get to the spot, and found all the pumpers upon the floor of the shaft, all stupefied with horror, though every one was there quite safe, and no rush of water was heard. Gravatt and Isambard were soon in the shield, where they observed that a small portion of clay had fallen from the top on the top floor. [marginal notes: A dreadful panic.]
 On the previous day Mr. Brunel had been formally appointed resident engineer.  Mr. Gravatt had been appointed an assistant engineer six months before. [editor’s note: William Gravatt (1806 – 1866), English civil engineer]