placed considerable emphasis on the value of a study of the rocky floor of the State, concerning which all we know at present is derived from the revelations of deep drillings at haphazard; and he thought it would be a good work for the State to make use of all accessible data of this kind at once in constructing a model of the rocky floor of the region under review. The care and fidelity with which he studied the underground geology are exemplified in a map attached to the paper on the oil and gas fields, in which the horizons of the Trenton limestone are indicated and approximately bounded as they occur by gradations ranging from fifty to two hundred and fifty feet, from elevations above the ocean level to one thousand and more feet below. Another contribution of Professor Orton's which may appropriately be given special notice is his part of the article on Ohio in the Encyclopædia Britannica, in which a succinct, clear, and comprehensive account of the geology of the whole State is given, with its salient features delineated so sharply that one may almost conceive from it a definite geological picture of the region.
Of all his scientific work, however. Professor Orton regarded the fixing of the order of the coal measures of Ohio as the most important; and he considered the determination of the order of the subcarboniferous strata, and particularly of the Berea Grit, as constituting a large permanent service to the study of the geology of the State.
At the recent meeting of the American Association for the Advancement of Science Professor Orton contributed a special paper on the local geology of Columbus, the place of the meeting, in which he dwelt largely on the origin of the drift that marks the superficial geology of the vicinity.
Of the work he has done for the increase and advancement of knowledge, the extent of a part of which we have only faintly indicated by the mention of a few particular researches. Professor Orton put the highest value on his labors as a teacher, a calling to which he was devoted for more than half a century. He found peculiar pleasure in instructing the children of the old pupils whom he had taught in his younger days. He was actively concerned in the promotion and extension of sanitary science, his addresses in that field having been one of the factors that led to the establishment of the Ohio State Board of Health. He was also greatly interested in the advancement of agriculture.
A theme on which Professor Orton was fond of dwelling in his public addresses was the amount and value of what has been accomplished within a comparatively short time in the world's history by the use of the methods of science. In an address delivered before