Here undoubtedly was a possibility. To drive three hundred yards of a heading large enough for a stooping man to pass through, would be a simple matter to men who had shown the skill of these conspirators. The soil was light and sandy, and they could use without suspicion as much timber as they required to shore up their work. It was true they would have to pass under the railway, but that again was a matter of timbering.
Their greatest difficulty, he imagined, would be in the disposal of the surplus earth. He began to figure out what it would mean. The passageway could hardly be less than four feet by five, to allow for lining, and this would amount to about two yards of material to the yard run, or say six hundred or seven hundred cubic yards altogether. Could this have been absorbed in the filling of the wharf? He thought so. The wharf was a large structure, thirty yards by thirty at least and eight or nine feet high; more than two thousand cubic yards of filling would have been required for it. The disposal of the earth, therefore, would have presented no difficulty. All that came out of the tunnel could have gone into the wharf three times over.
A tunnel seemingly being a practical proposition, he turned his attention to his second problem. How could he find out whether or not it had been made?
Obviously only from examination at one or other end. If it existed it must connect with cellars at the depot and the distillery. And of these there could be no question of which he ought to search. The depot was not only smaller and more compact, but it was deserted at intervals. If he could not succeed at the syndicate’s enclosure he would have no chance at the larger building.
It was true he had already searched it without result, but he was not then specially looking for a cellar, and with a more definite objective he might have better luck. He decided that if Benson went up to Hull that night he would have another try.
He took an afternoon train to Ferriby, and walking back towards the depot, took cover in the same place that he had previously used. There, sheltered by a hedge, he watched for the manager’s appearance.
The weather had, from the inspector’s point of view, changed for the worse. The sunny days had gone, and the sky was overladen with clouds. A cold wind blew in gustily from the south-east, bringing a damp fog which threatened every minute to turn to rain, and flecking the lead-colored waters of the estuary with spots of white. Willis shivered and drew up his collar higher round his ears as he crouched behind the wet bushes.
“Confound it,” he thought, “when I get into that shed I shall be dripping water all over the floor.”
But he remained at his post, and in due course he was rewarded by seeing Benson appear at the door in the fence, and after locking it behind him, start off down the railway towards Ferriby.
As before, Willis waited until the manager had got clear away, then slipping across the line, he produced his bent wire, opened the door, and five minutes later stood once more in the office.