Progress of the work—1886. No less than 76,400,000 bricks were used in the construction of the tunnel and bridges.
These bricks were vitrified bricks, from the Cattybrook Brick Company, near New Passage, on the Bristol and South Wales Union Railway; from the Fishponds and Bedminster Company, near Bristol; from Staffordshire; and from our own brick-yard, near the Five-mile-four-chain Shaft
The quantity from each is as follows :
| Catty brook | 19,125,440 |
| Fishponds | 7,229,100 |
| Staffordshire | 21,944,460 |
| Our own | 28,101,100 |
The quantity of Portland cement used on the works was 36,794 tons, the whole of which was brought from the Medway or the Thames, some by water to Newport, some by water direct to a wharf at the tunnel, but the greater part of it came by rail from Brentford, to which place it was carried in barges up the Thames.
The tonite used for blasting purposes amounted to about 250 tons, and several magazines had to be erected for the safe storage of this and other explosives.
The minimum quantity of water pumped when dealing with the Big Spring was 23 million gallons daily; the maximum quantity 30 millions. For more than a year the average quantity pumped daily was 24 million gallons.
