“That sounds right,” Seth nodded approvingly. “What’s go ter be done?”
“The job is by no means a difficult one,” Ernest Wilton answered. “In the first place, we must widen the shaft by a foot down to the level of the rock, that will give six inches all round. Then we must square off and level the top of the rock, which will then be a level shaft six inches wide all round. While you are doing this we must make a drum ready. That is easily made. We must make four circular frameworks, fasten twelve-feet planks, carefully fitted together, and pitched outside them so as to make it perfectly water-tight. We ought to have a layer of hydraulic lime or cement laid on the rock for the drum to rest on; but if we have not got them, some well-puddled clay will do as well. Then when the drum is in position in the shaft of rock, its upper end will be higher than the level of the water in the river, and if the rock is compact and free from fissures we shall be perfectly dry however deep we may sink. How are you off for strong planks? They must be strong to resist the pressure of the water and gravel.”
“I fear that we have no planks of that thickness whatever,” Mr Rawlings said. “We only brought enough timber for the scaffolding over the mine, and a little for framework if it wanted lining. You see, we did line it down to the rock. I think we have one balk of nine-inch timber left.”
“Let us measure it and see how many two-inch planks it will make.”
It was thirty-two feet long. Eight feet was therefore useless for planks, but would come in for the framework. Twenty-four feet would make eight planks of a little over two inches thick, nine inches wide, and twelve-feet long.
“This is less than a fifth of what we require,” Ernest Wilton said. “The shaft is eight feet in diameter, so we shall need some thirty-two nine-inch planks. However, there are trees about, not very large and not very high, but big enough to get one or two nine-inch planks twelve-feet long from each. The first thing to do is to get a supply of them.”
“And you feel quite sure that by lining this portion of the mine with a drum, as you describe, we shall get over our difficulty with the water?” Mr Rawlings said.
“Quite sure,” Ernest Wilton replied; “providing always that the rock is solid.”
“Then it’s as good as done,” Seth said emphatically. “You have put us on the right track, Wilton, and we’ll carry it through. I never thought about the river, and kept on wondering why that darned gravel kept letting the water through when it was as dry as bones when we drove through it.”
While the preparations were being made and parties scouring the country for timber the young engineer bent his mind to the task of inventing some better mode of getting rid of the water than by manual labour—the mine being sadly deficient in a lot of necessary gear, besides steam-power, as Ernest Wilton had quickly perceived, although he had refrained from commenting on the fact.