“Warming Up.”—“Warming up” is the expressive term of general currency, which Dr. E. G. Lancaster adopts to denote the process in which one starting on any work in a little while suffers a short period of fatigue, from which he soon recovers, to go on with new and increased vigor. This occurs in the course of walks, with students engaged in earnest reading or in writing, and in animals, as in dogs on the chase, the animals pursued, and racehorses. “It is said of two famous trotters, each of which has reduced the world’s record within a few years, that the period of warming up was very characteristic.... Athletes, especially ball players, realize the importance of practice just before the games, to be followed by a slight rest. A pitcher would hardly enter the box till he had got his arm in working order by a few minutes’ practice. Orators often are dull at first, but warm up. It is said that Wendell Phillips was often hissed for his slow, uninteresting speech, but rallied to the occasion at such times with his masterly oratory.” Dr. Lancaster has experimented on the phenomena, using a method like those of Mosso and of Lombard in the psychological laboratory at Clark University, and publishes the results, with details and curves, in the papers of the Colorado College Scientific Society. He tried ten or twelve subjects, experimenting on the middle finger of the right hand, and gaining most of his results from four or five persons. He finds that warming up is general, but not universal. One subject always did his best work first. He likewise showed no warming up in his mental work. The phenomenon called “second mind” is closely allied to warming up, but is not the same. The author is of the opinion that the importance of this process is greatly misunderstood.
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Sixty Years’ Improvements in Steamships.—A review of what has been accomplished in sixty years in the improvement of transatlantic traffic, given by Sir William H. White in his address at the British Association on Steam Navigation at High Speeds, shows that speed has been increased from eight and a half to twenty-two and a half knots an hour, and the time of the voyage has been brought down to about thirty-eight per cent of what it was in 1838. Ships have been more than trebled in length, about doubled in breadth, and increased tenfold in displacement. The number of passengers carried by a steamship has been enlarged from about one hundred to nearly two thousand. The engine power has been made forty times as great. The ratio of horse power to the weight driven has been quadrupled. The rate of coal consumption per horse power per hour is now only about one third what it was in 1840. Had the old rate of coal consumption continued, instead of three thousand tons of coal, nine thousand would have been required for a voyage at twenty-two knots. Had the engines been proportionately as heavy as those in use sixty years ago, they would have weighed about fourteen thousand tons. In other words, machinery, boilers, and coal would have exceeded the total weight of the Campania as she floats to-day. “There could not be a more striking illustration than this of the close relation between improvements in marine engineering at high speed. Equally true is it that this development could not have been accomplished but for the use of improved materials and structural arrangements.”
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American Advances in Forestry.—The Department of Agriculture having determined to prepare a book for the Paris Exposition, reviewing what has been accomplished in scientific agriculture in the United States, the Division of Forestry will contribute to it a short history of forestry in the United States, with an account of the efforts of private landholders to apply the principles of forestry. Much more has been accomplished in the United States in the way of forestry than has been supposed. Mr. Pinchot, the forester of the division, holds that wherever private owners have made the effort to use the merchantable timber on their woodland without injuring its productive power, and to establish new forests, there has been the intention of true forestry. The methods may have been imperfect, but they have tended toward economic forest management so far as their object was the continued use of the land for producing woods. Among the measures looking in this direction Mr. Pinchot mentions in his circular the practice which has been adopted “because it pays,” in some of the spruce lands of the Northwest, of leaving the small trees standing, so that the lumbermen can return for a second crop earlier than would otherwise be possible; and the adoption by farmers of methods in getting their wood, for saving the best trees and promoting their growth and that of the new ones; of keeping sprout lands to be cut over regularly and systematically, for periodical renewal, and of tree planting on waste places, hillsides liable to be washed, and the banks of streams. Other forms of planting are the institution of wind breaks in the treeless West, and special plantations for fence posts, etc. A kind of forestry practice is likewise indicated in the special pains that are taken by farmers and in lumbering districts to lessen the danger of fires. Forester Pinchot desires that all the information that can be gained be communicated to him for the proposed article.
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Professor Putnam on the Origins of the American Races.—In his address as retiring President of the American Association, Prof. F. W. Putnam, after expressing his high opinion of the late Dr. D. G. Brinton and his scientific labors, referred to the differences of opinion that had existed between them in respect to the origin of the American peoples, and proceeded to expound his own views on the subject. He regarded the term “mound-builders” as comprehensive enough to include all the peoples who had left the marks of their former presence in this country. Even the shell heaps could not be regarded as the work of one people. From the time of the earliest deposits—which were of great antiquity—to the present, such refuse piles had been made and many of the sites reoccupied, sometimes even by a different people. So with the mounds of earth and stone; many of them are of great antiquity, while others were made within the historic period, and even during the first half of the present century. These works were devoted to a variety of purposes, and there are many different kinds of them. Besides the mounds, there are groups of earthworks of a different order of structure, that must be considered by themselves—great embankments, fortifications, and singular structures on hills and plateaus that are in marked contrast to the ordinary conical mounds, and mounds in the form of animals and of man. The considerable antiquity of these older earthworks is proved by the accumulation of mold and the forest growth upon them. “If all mounds of shell, earth, or stone, fortifications on hills, or places of religious and ceremonial rites, are classed, irrespective of their structure, contents, or time of formation, as the work of one people, and that people is designated as the ‘American Indian’ or the ‘American race,’ and considered the only people ever inhabiting America north and south, we are simply ... not giving fair consideration to differences, while overestimating resemblances.” Citing analogies between our earthworks and Mexican structures, and looking upon the Pueblos as a connecting link, “we must regard the culture of the builders of the ancient earthworks as one and the same with that of ancient Mexico, although modified by environment. Our northern and eastern tribes came in contact with this people when they pushed their way southward and westward, and many of their arts and customs still linger among some of our Indian tribes. It is this absorption and admixture of the stocks that has in the course of thousands of years brought all our peoples into a certain uniformity. This does not, however, prove a unity of race.”
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Heat Insulators.—Mr. C. L. Norton has made experiments, at the request of Mr. Edward Atkinson, in order to determine the relative efficiency of several kinds of steam-pipe covering now on the market; to ascertain the fire risk attendant upon the use of certain methods and materials employed for insulation of steam pipes; to show the gain in economy attendant upon the increase of thickness of coverings; and to find the exact financial return that may be expected from a given outlay for covering steam pipes. A method of experimentation was adopted which represented as nearly as practicable the conditions existing in the actual use of steam pipes. Of sixteen non-conducting preparations tried, the most efficient were found to be those made of cork; next was a cover composed of an inner jacket of earthy material and an outer jacket of wool felt; and next magnesia. In reference to the last substance it is, however, observed that, while it is a most effective non-conductor, the name has been applied to many compounds of which the greater part consist of carbonate of lime or plaster of Paris, materials which are not good as heat retardents. Asbestos is merely a non-combustible material in which air may be entrapped, but, when non-porous, is a good conductor of heat. Generally speaking, a cover saves heat enough to pay for itself in a little less than a year at three hundred and ten ten-hour days, and in about four months at three hundred and sixty-five twenty-four-hour days. The decision as to the choice of cover must, however, come from other considerations, as well as from that of non-conductivity. Ability to withstand the action of heat for a prolonged period without being destroyed or rendered less efficient is of vital importance. The cork coverings were found to respond to this test extremely well, and there can be no question respecting magnesia; but Mr. Norton does not consider it safe to put upon a steam pipe wool, hair, felt, or woolen felt in any form, though the danger is not likely to accrue when an inch of fireproof material stands between the felt and the pipe. In general it may be said that if five years is the life of a cover, one inch is the most economical thickness, while a cover which has a life of ten years may to advantage be made two inches thick. The method of judging a pipe cover by the warmth felt on putting the hand upon it is fallacious; the sensation depends so much upon the nature of the surface that it utterly fails to give any idea of the actual temperature.
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