as a composite set is operated from outside, and that the Australian region was estimated that the same difficulty noted in passing from the paraboloidal form of attack. On May 2s de la Tripolitaine,” Renseignements Coloniaux et Documents, La Guerre Mondiale (1922); B. H. C. Jackson, Phil. Trans. Roy. Soc. (A), vol. 103, 1913) fractionated coal substance