'It is true,' said Brand, 'that our risks increase, but we have made such an important find in the very bottom of our mine that in spite of risk we cannot leave off increasing the danger. We have only forty men at work, and each man thoroughly understands the situation. All the men work under diver's conditions lest a breath of air should carry a lightning flash through a man, and each tool is handled with thick insulators. Were a man to wear an insulator through, and touch a tool with his bare hand, he would be killed; but every man knows that. We are working with five changes of men, and not stopping night nor day, except for Sabbath. Indeed, I have an emergency permit from the Executive to work Sabbath also, if circumstances make that step necessary.'
All this time we were running down a pretty steep incline; about one in ten I estimated it. I could see that Brand was not using the motor, that he was only holding us back with a foot-brake.
'How far have we to go,' I asked.
'About seventy miles in this carriage, and then straight down another half mile.'
'And this slope is about one in ten, is it not?'
'It is.'
'Then we shall be seven miles below the surface when the car stops and another half mile. You go a great depth for your electricity at Granby,' said I.
'We get something more than electricity here,' replied Brand. 'You will see shortly. We are more than half way, and I saw the storm signals at the electrometer as we passed. Whatever happens sit still, and have no fear.'
Blash! blash!! blash!!! in blue, red and blinding white light, accompanied by a crackling as of ten thousand little explosions, and then all was dark again. Was I struck blind? If so, the operation was painless, and I was not hurt in any other way. No, I could see again, and there was Brand at the brake, and the car was just going on as before, lit by its own lamp and sending rays before it by the headlight.
'That was a rather astonishing experience, Harry,' said Grayson; 'are we likely to have much more of it?'
'Yes, we shall see a lot of that kind. It is comparatively harmless. We might have walked through that and lived,' said Brand. 'We sometimes have to go through miles of what we call spearheads and flames, and to work amongst lightnings and thunders. So long as we are covered and insulated we are quite safe, but the men who work here are classed as first rank, which is equal to double the pay of ordinary miners, for they have to have rare fortitude and courage.'
Again blaze and glare, this time in yellow light, while the cavern
