CHAPTER X — AN EXPLOSION
Having given up all hopes of blowing up the bridge, Chris and his comrades turned their whole attention to the lines of waggons. The train that had come in on the previous evening had added to the number, although it had taken some of them away with it up country. They now made out that there were eight waggons piled with cases, that almost certainly contained rifles; six with tarpaulins closely packed over them, and these they guessed contained ammunition boxes; four, each with two large cases that might contain field guns; while the two with what they were sure were big guns still remained on the siding.
"I should say that about four or five pounds of dynamite would be an abundance for each of those ammunition waggons; less than that would do, as we could, by slitting the tarpaulins, put a pound among the cases, and if one case were exploded it would set all the others off. There is no trouble about them. I will just take a note. They are on the second siding; there are eight other waggons in front of them and six behind, so we cannot make any mistake about that. There must be a good heavy charge under the rifle trucks, for we shall have to blow them all well into the air to bend and damage them enough to be altogether unserviceable. As for the guns, and especially the heavy ones, it is a difficult question. Of course, if we could open the cases and get at the breech-pieces, and put dynamite among them, we could damage all the mechanism so much that the guns would be useless until new breech-pieces were made, which I fancy must be altogether beyond the Boers; but as there is no possibility of opening them, we must trust to blowing the guns so high in the air that they will be too much damaged for use by the explosion and fall. We have got altogether two hundredweight; now two pounds to each ammunition waggon will take twelve pounds. What shall we say for the rifles?"
"Ten pounds," Brown suggested.
"That would take eighty more pounds," Willesden objected, "which would make a big hole in our stores."
"We must have a good charge," Chris said. "Suppose we say nine pounds to each, that will save eight pounds; fifteen pounds apiece ought to give the eight cases which we suppose hold field-guns a good hoist; that will leave us with over a hundred pounds, fifty for each of the big guns. Now that we have seen all that is necessary, we may as well be off and begin to get ready."
The covers were taken off the boxes of dynamite, and these were unscrewed, and the explosive was with great care divided into the portions as agreed upon. Two of the cases furnished just sufficient for the ammunition waggons and the two big guns, the other two for the smaller cannon and the trucks with the rifles. The charges were sewn up in pieces of the canvas, the smaller charges for the ammunition boxes being enclosed in thinner stuff that had been sewn under the canvas used in packing; the fuses and detonators were then cut and inserted. Chris was perfectly up in this work, having performed the operation scores of times in the mines. The length it should burn was only decided after a discussion.
There would be in all nineteen charges to explode, and these were in three groups at some little distance from each other, all the cannon being on the same siding. It would be necessary, perhaps, to wait for some time till all these were free from observation by natives or others who might be moving about the yard, then a signal must be given that they could all see. It would not take long to light the fuses, for each of them would be provided with a slow match, which burns with but a spark, and could be held under a hat or an inverted tin cup till the time came for using it. The question was how far must they be away to ensure their own safety, and Chris maintained that at least four or five hundred yards would be necessary to place them in even comparative safety from the rain of fragments that would fall over a wide area. Finally it was agreed to cut the fuses to a length to burn four minutes; this would allow a minute for any hitch that might occur in lighting them, and three minutes to burn. It was of course important that they should be no longer than was absolutely necessary, as there existed a certain risk that one of the little sparks might be seen by a passing Kaffir, or, as was still more probable, the smell of burning powder should attract attention. It was agreed that Chris should light the fuses at the cannon, which were farthest from the others, that Peters should see to the six rifle trucks, and Willesden and Brown attend the eight trucks with the ammunition, one to begin at each end of the line.