to the interests of their progress to save the whole archipelago from the irruptions of interstellar magnetism or bacterial life. But even this was found to have serious disadvantages. Unbroken prosperity surcharged the leaders of the other islands with conceit, and made them lose their fear of the central isle and resume their projects for its conquest; or it deluged them with population, which, whenever nature grew economical again, was driven to foreign means for its sustenance, and, at times, goaded by hunger, made in military wise for the isle of devils. Yet these alarms and dangers were more infrequent and more easily repelled than when the more ambitious of the archipelago were driven by the spur of famine and disaster to incursion. And, though for a brief period the Limanorans allowed an occasional tornado or plague to devastate the islands of hostile neighbours, they came to the conclusion that it needed less of their energy to repel an occasional hive of enemies impelled by narrowing limits or the lessening generosity of nature than to beat off vast bodies of embattled peoples frantic with hunger and reckless of life, led by the keenest skill and fieriest ambition of the archipelago. They could better avoid all destruction of life in the one case than in the other,--one of the duties of their civilisation, even though a subsidiary one. The Piramo were thus essential to the progress of the race; their growing knowledge of the conditions that governed the climate as well as the passing weather saved in a day as much power as the use of such an instrument as the pirakno at first could add to Rimla in a year. And the scene of the labours of the Piramo was every year more and more extended to the extra-terrene; meteorology became in its investigatory and experimental department more and more cosmic, and often overlapped astronomy, astrobiology, and astrophysics, and aided them; more and more did they find their problems questions of magnetism or electricity. In the interstellar spaces must be sought the sources of the greater disturbances of season and climate and the pirakno grew every year of more and more importance, as they traced the magnetic influences around the earth back into the infinite fields of space.