Choosing his moment, Nordenholt announced that, in future, the factories would be run continuously, shift after shift, throughout the twenty-four hours. For a time he called a halt to the newspaper campaign for increased output. He would need this form of publicity later; and he did not wish it to become staled by constant repetition. For the present he was satisfied. Everything was now in train and he was into his stride all along the line. At last statistics were accumulating which would enable him to gauge exactly how the machinery was running; and he held his hand until a balance-sheet could be drawn with accuracy. * * * * * At this point in my narrative I am trying to produce a conspectus of the Nitrogen Area as it was during that period in its career. I leave to the imagination of my readers the task of picturing that gigantic concentration of human effort: the eternal smoke-cloud from a thousand chimney-stalks lying ever between us and the sun; the murky twilight of the streets at noon; the whir of dynamos and the roar of the great electric arcs; the unintermittent thunder of trains pouring coal into the city; and, above all, the half-naked figures in the factories, toiling, toiling, shift after shift in one incessant strain through the four-and-twenty hours. No one can ever depict the details of that panorama. But alongside this vast outpouring of physical energy there lay another world, calm, orderly and almost silent, yet equally important to the end in view: the world of the scientific experts in their laboratories and research stations. To pass from one region to the other was like a transition from pandemonium to a cloister. Nordenholt had grouped his experts into three main classes, though of course these groups by no means included all the investigators he controlled. It was here that the Nordenholt Gang were strongest, for the path of the scientific man is one which offered the greatest chances to Nordenholt’s scheme for the furthering of youth. In the first place came the group of chemists and electricians who were engaged upon the improvement of nitrogen fixation methods; and between this section and the factories there was a constant _liaison_; so that each new plant which was erected might contain the very latest improvements devised by the experts. The second group contained the bacteriologists, whose task it was to investigate the habits of _B. diazotans_, to determine whether it could be exterminated in any practical manner and to discover what methods could be employed to prevent its ravaging the new crops when they were obtainable.