Societies and Academies

Abstract

LONDON. Institution of Mining and Metallurgy, October 19 —Mr. H. Livingstone Sulman, president, in the chair.— H. Standish Ball: The economics of tube milling. The investigation, of which this paper is a report, was undertaken by the author at the McGill University, Montreal, for the purpose of determining the most efficient working conditions of the tube-mill on metal-bearing ores. An experimental tube-mill was constructed, with all necessary accessories, and a series of test runs was made under various conditions of feed, moisture, pebble load, and speed, the system adopted being that in each series of tests one of the above factors was varied whilst the others were maintained as constants. Taking the experimental mill as a standard, the result of the tests was to establish certain conditions for each of the four factors mentioned as those most conducive to efficiency; and the author believes that there is a possibility of estimating from the curves obtained from the different tests the probable results that would be derived from running the mill under different conditions. He deduces from this the rather startling theory that in any mill it would be possible by a similar series of tests to obtain the necessary information for running it to the best advantage. Among other results of his experiments he was able to ascertain the duration of time required by a mill to assume a uniform condition following a change of adjustment of its various component factors, and to test the efficiency of the mill during the transition periods. Having ascertained by tests the several conditions under which the mill worked at its best, a trial was made during which the critical factors were all complied with, and the resultant mechanical efficiency was found to show an increase of 14 per cent, above all previous tests, thus seeming to bear out the utility and value of experimental work in determining the proper conditions of working.—Eugene Coste: Fallacies in the theory of the organic origin of petroleum. The author sets out to show that the supporters of the organic theory founded their arguments on erroneous premises, and ignore the obvious facts presented by the petroleum occurrences and deposits, which point to a volcanic origin In proof of his own theory he directs attention to the abundance of hydrocarbon emanations noted in connection with volcanic phenomena, as showing that the sources of carbon, are not confined to the organic kingdom alone. The conclusion at which he arrives is that the constant recurrence of hydrocarbons in volcanic and igneous rocks, in volcanic emanations, in metallic and other veins, in meteorites, in comets and other stellar bodies, clearly demonstrates that petroleums are not organic, as if they were their distribution could not possibly resemble the actual occurrences which are met with. The petroleum deposits are not everywhere associated with rocks of a particular age, but are found in strata of all ages, and only along some of the tectonic disturbances; where there are no such disturbances the strata are barren. These occurrences are therefore, he claims, due to dynamic disturbances accompanied by magmatic emanations from the interior, which must be held to be of solfataric volcanic nature, and unlike anything else known to be to-day in the active process of formation in nature.