In the midst of the bustle of these preparations for the future (if anything the Limanorans did could be called bustle), there occurred an accident that smote them almost with dismay, and brought them as near as I had ever seen them approach to melancholy. The additions to the sources of the energy available in Rimla had entailed more muscular work as well as more superintendence, and it was necessary to assign more physical toil to the now-earlier mature than had been customary. Two scions of the meteorological families, who had been selected for marriage and parentage, were sent to manage a large pirakno, which had been constructed for drawing the magnetism from the air and the spaces just beyond the atmosphere. The great machine had been placed on an isolated spur of Lilaroma, so that if ever through the sudden sweeping of the earth into a supermagnetised area it should become dangerous, it could easily be detached from Rimla and insulated. And there were never less than two beside it to help in its management. The younger men and women took the night watches in all the physical labour that had to be undertaken. And Tamarna and Omirlo, as one of the youngest and least experienced of the pairs that had to manage this huge pirakno, kept the last watch of the night, the watch that included sunrise and was followed by that of two of the most mature workers. It was thought that, as every Limanoran would be awake and on the alert at dawn, help in any emergency could easily be procured. As it was well known that during that period there was a great increase of magnetism in the atmosphere, provision was made in the machine itself for so regular a change; it was so arranged that, when the sun’s rays first touched it, it should automatically increase its capacity for magnetism. But so recent had been the development of cosmic magnetography that the times and seasons of the irregular increase of magnetism had not been tabulated and classified. Had the observations been made for a long enough time to allow of inferring a uniformity or law, then it would have been seen that these supermagnetised spaces, though they may have been entered by the earth during the night, have little effect upon her atmosphere till day dawns; the excess of magnetism seems to lie dormant in the dark; the first rays of the sun act like a fuse to a mine and complete the circuit between extra-terrene space and the surface of the earth. Sunrise, in fact, as they came afterwards to see, was the most critical time for such a machine as the pirakno.