This was a cavernous galvanized, iron shed the size of a large aircraft hangar. At least one hundred yards long and fifty feet high, it was filled with long rows of the cylindrical tube mills.
Forty of them in all, they were as thick as the boiler of a steam locomotive and about twice as long. Into one end of them was fed the ore which had been reduced in size by the jaw crushers. The tube mills revolved and the loose steel balls within them pounded the rock to powder.
If the noise before had been bad, it was hideous in the mill room.
Rod and Herby made no effort to speak to each other until they had walked through into the comparative quiet of the first heavy-media separator room. 'Now,' Herby explained. 'This is where we start worrying.' He indicated the rows of pale blue six-inch piping that came through the wall from the mill room.
'In there is the powdered rock mixed with water to a smooth flowing paste. About forty percent of the gold is free.'
'No one can get into those pipes and you've checked for any possible leak?' Rod asked. Herby nodded.
'But,' he said, 'have a look here. Along the far wall was a series of cages. They were made of heavy steel mesh, the perforations would not allow a man's finger through. The heavy steel doors were barred and locked. Outside each battery of cages stood a Bantu attendant in clean white overalls. They were all concentrating on the manipulation of the turricock that obviously regulated the flow of the powdered ore through the pipes.
Herby stopped at one of the cages.
'Shine!' He pointed. Beyond the heavy guard screen the grey paste of rock powder was flowing from a series of nozzles over an inclined black rubber sheet. The surface of the rubber sheet was deeply corrugated, and in each corrugation the free gold was collecting, held there by its own weight. The gold was thick as butter in a Dagwood sandwich, greasy yellow-looking in the folds of rubber.
Rod laid hold of the steel screen and shook it.
'No,' Herby laughed. 'No one will get in that way.'
'How do you clean the gold off that sheet? Does someone have access to the separator?' Rod asked.
'The separator cleans itself automatically,' Herby answered. 'Look!'
Rod noticed for the first time that the rubber sheet was moving very slowly, it was also an endless belt running round two rollers. As the belt inverted, so fine jets of water washed the gold from the corrugations into a collection tank.
'I'm the only one who has access. We change the collection tanks daily,' said Herby.
It looked foolproof, Rod had to admit.
Rod turned and glanced down the row of four Bantu attendants. They were all intent on their duties, and Rod knew that each of them had a high security rating. They had been carefully selected and screened before being allowed into the reduction works.
'Satisfied?' Herby asked.
'Okay,' Rod nodded, and the two of them went out through the door in the far wall. Locking it behind them.
Immediately they had gone the four Bantu attendants reacted. They straightened up, the scowls of concentration smoothed out to be replaced by grins of relief. One made a remark and they all laughed, and opened the waist bands of their tunics. From inside each trouser leg they drew a length of quarter-inch copper wire and began probing them through the steel screen.
It had taken Crooked Leg, the photographer, almost a year to work out a means of milking gold from the heavily screened and guarded separators.
The method which he had discovered was, like all workable plans, extremely simple.
Mercury, quicksilver, absorbs gold the way blotting paper sucks up moisture.' It will suck in any speck of gold that comes in contact with it. Mercury has a further property, it can be made to spread on copper like butter on bread. This layer of mercury on copper retains its powers of absorbing gold.
Crooked Leg had devised the idea of coating lengths of copper wire with mercury. The wire could be inserted through the apertures in the steel mesh and the wire laid across the corrugated rubber sheet, where it set about mopping up every speck of gold that flowed over it. The lengths of wire could be quickly slipped down the trouser leg at the approach of an official, and they could be smuggled in and out of the reduction works the same way.
Every evening Crooked Leg retrieved the gold-thickened wire, and issued his four accomplices with newly coated lengths. Every night in the abandoned workings beyond the ridge he boiled the mercury to make it release its gold.
'Now,' Herby could speak normally in the blessed quiet of the cyanide plant, 'we have skimmed off the free gold and we are left with the sulphide gold.' He offered Rod a cigarette as they made their way between the massive steel tanks that spread over many acres. 'We pump this into the tanks and add cyanide. The cyanide dissolves the gold and takes it into solution. We tap it off and run it through zinc powder. The gold is deposited on the zinc, we burn away the zinc and we are left with the gold.' Rod lit his cigarette. He knew all this but Herby was giving him a Cooks' tour for visiting VIPS. He flicked his lighter for Herby. 'There is no way anyone could swipe it when it's in solution.' Herby shook his head, exhaling smoke. 'Apart from anything else, cyanide is a deadly poison.' He glanced at his watch.
'Three-twenty, they'll be pouring now. Shall we go across to the smelt house?' The smelt house was the only brick building among all the galvanized iron. It stood a little isolated. Its windows were high up and heavily barred.
At the steel door Herby buzzed, and a peephole opened in the door.
He and Rod were immediately recognised and the door swung open. They were in a cage of bars which could only be opened once the door was closed behind them.
'Afternoon, Mr. Ironsides, Mr. Innes.' The guard was apologetic.
'Would you sign, please?' He was a retired policeman with a paunch and a holstered revolver on his hip.
They signed and the guard signalled to his mate on the steel catwalk high above the smelt room floor. This guard tucked his pump action shotgun under one arm, and threw the switch on the walk beside him.
The cage door opened and they went through.
Along the far wall the electric furnaces were set into the brickwork.
They resembled the doors of the bread ovens in a bakery.
The concrete floor of the room was uncluttered, except for the mechanical loader that carried the gold crucible in its steel arms, and the moulds before it. The half dozen personnel of the smelt house barely looked up as Rod and Herby approached.
The pour was well advanced, the arms of the loader tilted and a thin stream of molten gold issued from the spout of the crucible, and fell into the mould. The gold hissed and smoked and crackled, and tiny red and blue sparks twinkled on its surface as it cooled.
Already forty or fifty bars were laid out on the rubber-wheeled trolley beside the mould. Each bar was a little smaller than a cigar box. It had the knobby bumpy look of roughly cast metal.
Rod stopped and touched one of the bars. It was still hot and it had the slightly greasy feeling that new gold always has.
'How much? 'he asked Herby, and Herby shrugged.
'About a million rand's worth, perhaps a little more.' So that's what a million rand looks like, Rod mused, it's not very impressive.
'What's the procedure now? 'Rod asked.
'We weigh it, and stamp the weight and batch number into each bar.' He pointed to a massive circular safe deposit door in the near wall. 'It's stored there overnight, and tomorrow a refinery armoured car will come out from Johannesburg and pick it up.' Herby led the way out of the smelt house. 'Anyway, that's not the trouble. Our leak is sucking off the shine before it ever reaches the smelt house.'
'Let me think about it for a few days,' Rod said. 'Then we'll get together again, try and find the solution.' He was still thinking about it now. Lying in the darkness and smoking cigarette after cigarette.
There seemed to be only one solution. They would have to plant Bantu police in the reduction works.
It was an endless game involving all the mining companies and their reduction plant personnel. An inventive mind would devise a new system of sucking off the shine.
The Company would become aware of the activity by comparison of estimated and actual recovery and they would work on the leak for a week, a month, sometimes a year. Then they would break the system.
There would be prosecutions, stiff gaol sentences, and the Company would circularize its neighbours, and they would all settle back and wait for the next customer to appear.
Gold has many remarkable properties, its weight, its non-corruptibility and, not least, the greed and lust it conjures up in the hearts of men.
Rod stubbed his cigarette, rolled onto his side and pulled the bedclothes up over his shoulders. His last thought before sleep was for the major problem that, these days, was never very far from the surface of his mind.
The Delange brothers had driven almost 1,500 feet in two weeks. At this rate they would hit the Big Dipper seven weeks from now, then even
