unselfish labor. Prof. S. W. Robinson, addressing the Mechanical Section on the education of the engineer, made incidental reference to invention as an aim in class work. Admitting that ingenuity of the highest order rests upon an incommunicable somewhat, he argued that inventiveness of a valuable kind was quite within the scope of teaching. In the department of machine design he believed lay a field for eliciting the originality of students; the several parts of a machine could be studied with a view to their improvement, and then the machine as a whole could be redesigned. Time was when it was considered artistic to give a machine or engineering structure the outlines of the Greek orders; to-day a design which is seen to be strong, rigid, and economical is found to lend itself to a beauty of form impossible to borrowed lines, however graceful in themselves.
Prof. C. A. Walcott, in his discourse on geological time as indicated by the sedimentary rocks of North America, prepared the hearer for the address of Prof. Joseph Le Conte, as retiring president, on the origin of mountain ranges. This address in matter and spirit was a master's lesson in scientific method. Without the waste of a word Prof. Le Conte lucidly explained the theory of mountain birth which science owes to him and to Prof. J. D. Dana. That sea margins have everywhere been the seat of mountain emergence was declared to be a fact of observation; that the physical cause for this fact is mainly the shrinking of a cooling and practically viscous planet, seeking equilibrium, was argued with a judicious weighing of the objections urged by T. Mellard Reade and other critics. For all the natural affection that a thinker must bear the child of his brain, Prof. Le Conte claimed no more than that the probabilities were in its favor, leaving the last and unappealable verdict to be uttered only when all the evidence has been discovered and passed upon. Contrasted with the scientific erudition of this address was Dr. D. G. Brinton's popular introduction to The Earliest Men on the following evening at the public session. Choosing apt and simple illustrations, he showed how the anthropologist, from remains which seem rather scanty, is able to piece together a picture of primitive men. That they had compassion and skill enough among them to nurse the helpless for months together was, for example, proved by adducing the bones of a man who had suffered a compound, comminuted fracture, and survived the misfortune several years.
One of the liveliest sectional discussions arose among the botanists on the reading of Prof. C. R. Barnes's paper on The Food of Green Plants, in which paper it was maintained that the protoplasm of plants and animals is identical. Prof. N. L. Britton could not see how the profound divergences between animals and plants, in their highest forms, could have arisen, except through elemental differences in protoplasm. Prof. C. MacMillan also demurred to the dictum of Prof. Barnes: animals are analytic, energy-producing; plants are synthetic, energy-absorbing; that plants have a certain superiority over animals comes out, he argued, in their comparative superabundance. In this section Prof. C. MacMillan also read a brief paper, proving how seriously botany is neglected as a study in American colleges and universities, many biological laboratories being devoted chiefly to instruction in zoölogy. The section voted that through the proper official channels the Department of Agriculture, at Washington, be requested to print and circulate Prof. MacMillan's paper.
To the chemists Prof. E. W. Morley detailed the refined methods by which he assigns to oxygen a specific gravity of 15·882, as a result of twenty recent determinations. An apparatus for ascertaining expansions was exhibited by Prof. Morley, its inventor, and Prof.