Part 12

=“Winking.”=--No satisfactory determination has been made of the reason we wink. Some suppose that the descent and return of the lid over the eye serves to sweep or wash it off; others that covering of the eye gives it a rest from the labor of vision, if only for an inappreciable instant. This view borrows some force from the fact that the record of winking is considerably used by experimental physiologists to help measure the fatigue which the eye suffers. In another line of investigation Herr S. Garten has attempted to measure the length of time occupied by the different phases of a wink. He used a specially arranged photographic apparatus, and affixed a piece of white paper to the edge of the eyelid for a mark. He found that the lid descends quickly, and rests a little at the bottom of its movement, after which it rises, but more slowly than it fell. The mean duration of the downward movement was from seventy-five to ninety-one thousandths of a second; the rest with the eye shut lasted variously, the shortest durations being fifteen hundredths of a second with one subject and seventeen hundredths with another; and the third phase of the wink, the rising of the lid, took seventeen hundredths of a second more, making the entire duration of the wink about forty hundredths, or four tenths of a second. The interruption is not long enough to interfere with distinct vision. M.V. Henri says, in _L’Année Psychologique_, that different persons wink differently--some often, others rarely; some in groups of ten or so at a time, when they rest a while; and others regularly, once only at a time. The movement is modified by the degree of attention. Periods of close interest, when we wink hardly at all, may be followed by a speedy making up for lost time by rapid winking when the tension is relieved.

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=An Ingenious Method of Locating an Obstruction.=--The Engineering Record gives the following interesting account of the scientific solving of a practical commercial problem: “The pneumatic dispatch tube for the delivery of mail between the main Philadelphia post office and a branch office at Chestnut and Third Streets is a cast-iron pipe buried below the surface of the street, and in it small cylindrical carriers, six inches in diameter, are propelled from end to end by air pressure. At one time a carrier became lodged at some unknown point in the tube, and to remove the obstruction it was desirable to locate its position as closely as possible before digging down to the pipe. This was satisfactorily accomplished by firing a pistol at one end of the tube; its report was echoed from the obstruction, and indicated its position by the time required for the transmission of the sound. The pistol was fired in a hole in the side of the pneumatic tube near the end, which was capped and had a rubber-hose connection to the recording apparatus. The end of the rubber hose terminated in a chamber closed by a diaphragm about five inches in diameter, which had a stylus attached to it. A cock in the middle of the rubber hose was partly closed to reduce the force of the explosion on the diaphragm, and the pistol was fired. The sound-wave immediately produced a movement of the diaphragm, causing the stylus to make a mark on the record diagram. The hose cock was then fully opened, and when the sound-wave had traveled to the obstruction and been reflected back it again moved the diaphragm, and caused the stylus to make a second mark on the diagram. The lapse of time had been automatically recorded on the same diagram, so to determine the distance it was only necessary to note the exact interval of time between the direct and reflected reports, divide it by two, and multiply the quotient by the velocity of sound under the existing conditions.” The obstruction was indicated at 1,537 feet from the diaphragm. Excavations were made at this place, and the carrier was found nearly at the calculated point. The limits of distance at which this method is applicable have not yet been determined, but Mr. Batcheller, the engineer of the Pneumatic Tube Company and the deviser of the above ingenious expedient, has found that in a tube 43.3 inches in diameter a pistol shot will vibrate a sensitive diaphragm at a distance of 65,129 feet; decreasing the diameter of the tube decreases the distance over which the pistol shot will act.

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=Diseased Meat in Paris.=--The police of Paris, says the Lancet, have just laid hands on a vast fraudulent organization for evading the precautionary measures drawn up by the authorities for inspecting the meat distributed for consumption in the suburbs of Paris. Both for Paris and the suburbs all animals destined for food have to be killed in public slaughterhouses, where the strictest watch is kept by the municipal veterinary surgeons, who forbid the delivery to the butchers of any meat which exhibits the slightest suspicious signs. Elaborate regulations have been laid down as to the various diseases which render meat unfit for the food of man, and naturally enough tuberculosis is the complaint most rigorously watched for. The swindlers who have been arrested made up a vast organization which used to buy up from the farms of the eastern provinces and even in Germany such animals as, owing to disease, would have been refused for slaughter at the abattoirs, and, moreover, they bought them dirt cheap. These animals were then conveyed in regular herds to a small place near Paris and killed in sheds built at the bottom of an old quarry. Under cover of night the meat was taken away by the accomplice butchers and resold in the various suburban shops. In connection with this clandestine slaughterhouse the firm had a kind of cemetery, where those animals were buried the meat of which was too bad for even the swindlers to risk its sale in the market. Ivry was the place where the fraud was discovered, and the official inquiry shows that the organization was singularly complete. It is extraordinary that the slaughterhouse, which was in full work, should never have attracted the attention of the villagers, but it must be remembered that all killing was done by night and that the slaughtermen were all Germans who did not understand a word of French, and were therefore unable to engage in imprudent conversation with the neighbors.

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=How Aluminum is made.=--In a paper read before the Manchester Junior Electrical Engineers, J. H. Henderson describes the two commercial methods of making aluminum: The agent which has made aluminum a commercial product is electricity. This is how electrolysis produces it (by one successful method): In a metal, carbon-lined crucible having two carbon electrodes, one of which acts as anode and the other as cathode, are put the following ingredients: Fluoride of calcium, 234 parts by weight; double fluoride of cryolite, 421 parts by weight; fluoride of aluminum, 845 parts by weight. To these add three to four per cent of a suitable chloride--for example, calcium chloride. To this add alumina sufficient to form a very stiff mixture. Before electrolysis can begin the above are fused by means of heat, which should not exceed 1,210° F. The heat is obtained from a furnace heated by gas, coke, or charcoal, care being taken that no gases from the furnace enter the crucible. The bath fused, the electrodes are dipped into it, the current switched on, and the metal is deposited (in the best and largest of these crucibles) at the rate of one pound per five electrical horse-power hours. The current pressure required is six to eight volts, at a density of one and a half ampères per square inch. The metal from time to time is removed from the crucible by means of a siphon or a ladle, care being taken to remove as little of the haloid salts as possible. There is another method of extraction equally successful with this, but also more economical. In this other method a set of similar ingredients are placed in a crucible having one or more vertically movable carbon electrodes, which are used as one, or a collective anode, respectively. The crucible, though lined principally with carbon, has some metal exposed to act as a cathode at the beginning of the process, this to generate heat enough to fuse the bath, after which the anode is placed so that the extracted aluminum acts as a cathode. The molten metal is from time to time run out of a tap-hole into a mold, and thence cast into ingots, or granulated by being poured into cold water. The same particulars as to results apply to this crucible furnace process also, only that not nearly so much of the bath is wasted in it, and the metal needs less purifying when molten. There are, also, no loss of time and money from the use of gas, coke, or charcoal, and of an extra furnace in this method.

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=“A Mechanical Bootblack.”=--A bootblacking apparatus is one of the latest developments of the nickel-in-the-slot machine, a specimen of which is undergoing trial in a French public garden. The customer drops his coin--in the present case a ten centime, or a two-and-a-half-cent piece--into the receptacle, which opens the way to a compartment where a brush cleans his boots; he next puts his feet into a second compartment and has them blackened; and then into a third, where they are polished. The operation takes about a minute and a half, and during the time the customer may watch the indications of its progress as they are shown upon the dial. The machinery working in the inside is very simple. An electric motor of small power--about eighteen kilogrammetres per second--controls the shaft on which the three rotary brushes are fixed, and the customer has only to unlock the machine, the same as all others of its kind, with his coin, and move the handle which opens the circuit and starts the motion. A representation of the machine at work is given in the accompanying illustration, for which we are indebted to _La Nature_.

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=The “Barisal Guns.”=--A curious phenomenon of unexplained sounds like those of explosions, occasionally heard in different places over the earth, has attracted much attention, has been made the subject of a book recording several hundred accounts of it, by M. Ernest Van den Broeck, of Brussels, and has already been mentioned in the Popular Science Monthly. The phenomenon has been most carefully observed in India, where it seems to have assumed a peculiarly marked form, and is known there as the “Barisal guns.” M. Van den Broeck calls it “mistpoeffers,” or air-puffs. The most definite description of it is given in Nature by Mr. Henry S. Schurr, as he has heard it in India, where it has been observed over a wide range, but most clearly and frequently in the Baekergunge district, of which Barisal is the headquarters. The Barisal guns are heard most frequently from February to October, not during fine weather but just before, during, or immediately after heavy rain. They always sound in triplets--that is, three reports occur, one after another, at regular intervals--and though several guns may be heard, the number is always three or a multiple of three. Sometimes only one series of triplets of sounds is remarked in a day; at other times the author has counted as many as forty-five of them, one after another, without a pause. The report is exactly like the firing of big guns heard at a distance, except that it is always double, or has an echo. A number of conjectural solutions of the phenomenon have been put forth, but none of them accounts for it as a whole in any approaching a satisfactory manner.

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=Photographing Live Fishes.=--A number of methods are mentioned by Dr. R. W. Schufeldt, in a paper on the subject, by which fishes may be photographed in their natural element, with natural surroundings. This can be done, even under the surface of the water, by the use of certain subaquatic apparatus. By the employment of instantaneous photography some fishes have been taken in the air, as of salmon in the act of leaping, or of flying fish in flight. Such pictures, however, illustrate special habits rather than the ordinary life of the subjects. Well-arranged aquariums afford opportunities for photographing fishes in almost every condition and position, and a command of light and situation can be had in them which is of great advantage to the operator. The specimens of fish photographs published by the author with his paper are in every way satisfactory. The spots on the sunfish, for example, are almost as clear and distinct as if we had the fish lying before us in the broad light. The photograph of the pike has afforded opportunity to correct some inaccuracies in the drawing of it as given in previous works of high authority.

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=Marine Life at Cold Spring Harbor, Long Island.=--Mr. Francis N. Beach, in presenting to the Boston Society of Natural History a list of the Marine Mollusca of Cold Spring Harbor, Long Island, speaks of the locality as representing “a fairly distinct facies of molluscan life--the fauna of the oyster beds, broadly speaking. From this point of view, its homogeneity and the absence of stragglers lend it value. Probably almost every species enumerated lives on the spot where found or in the immediate vicinity. This characteristic makes the spot a good sample of actual conditions of life in that interesting transitional region where the ‘Virginian’ and ‘Acadian’ (or ‘Boreal’) faunas overlap. From this point of view it is, so far from being homogeneous, strikingly heterogeneous.” Of the two faunas, the southern one contributes a quota rather more than twice that of the more northern one, and the increase in the preponderance of southern forms can be detected in a range of forty miles. The author concludes from his examination that, notwithstanding the well-marked character of Cold Spring Harbor as “muddy,” its molluscan fauna is determined not at all by that character, but predominantly by the depth of water and by the factors included in the “inclosedness” of the place--that is, he supposes, by the temperature, the specific gravity, the percentage of organic matter, etc. “It looks as though the various species would manage somehow to be represented on almost any stretch of shore or bottom, provided only the _water conditions_ be right.”

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=Farm Homes for Neglected City Children.=--The system of providing homes upon farms is represented in the last annual report of the New York Juvenile Asylum as being on the wane. While from 1880 to 1890 twenty-four per cent of the children committed to the asylum were placed in Western homes, the percentage from 1890 to 1897 was only fifteen. Among the reasons assigned for this diminution are the increase of undesirable material, chiefly of races against which prejudice is strong, and the growing habit of parents expecting their children to be restored to them when their services become profitable. Placing out street waifs and neglected and dependent children in the homes of private families, the report says, has been sadly abused. The degradation and moral corruption of the condition of such children are apt to make them so refractory and unsusceptible to the wholesome influences of family life that an abrupt transfer is liable to be attended with failure and disaster. The children should therefore be previously brought under the restraining and reformatory influences of a training school. At the best, a placing-out work can not be exempt from serious contingencies. “The second decade, the adolescent age, under most favorable conditions, is the period when the will is apt to be wholly dominated by the emotions, and unless the environment is peculiarly favorable, guardianship becomes a difficult function. With an indenturing system that prolongs the term of apprenticeship for boys throughout their minority, both apprentice and guardian must possess an extraordinary measure of amiable qualities to insure a continuance of their relation through an extended period.” When the boy is old enough to earn wages from strangers the temptation to leave and go out for hire is very strong, and must be met by a corresponding degree of tact and liberality; and even when interests are happily adjusted “a placing-out system ought to take account of the tastes and aptitudes of young people, and leave the way open for the deserving at a suitable age to start upon a new career.”

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=Animals Helping One Another.=--While the ruminant animals as a rule do not seem to have made any further advance toward forming communal groups than to post sentinels while pasturing together, a few marked cases are found in which a division of labor and some system of assistance seem to have been given effect. One such instance is cited in the London Spectator as having been observed by Lord Lovat in the Highland deer, where large stags have smaller stags to attend them and serve them very much as the English school bully is attended and served by his fag. Lord Lovat tells another story of compassion manifested and help afforded by a stag to a younger animal. Of three stags on the move, two jumped the wire fence, and the third, a two-year-old, halted and would not venture the leap. The two waited for some time while the little fellow ran along the fence, till the larger of them came back to coax him, and “actually kissed him several times.” Finally, the animal gave up and went on, after which the little stag took courage and made the jump. The social organization is very far advanced with the beavers, and is quite elaborate with the rabbits, which excavate common and interlacing burrows, and with insects like ants and bees.

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=Geological Formations and Forests in New Jersey.=--From a study of the relation between forestry and geology in New Jersey, Arthur Hollick finds that two distinctly defined forest zones have long been recognized in the State--a deciduous and a coniferous--the contrast between the two being so obvious as to attract the attention even of superficial observers. While the deciduous zone is roughly confined to the northern part of the State and the coniferous to the southern part, yet when the line of demarcation is carefully followed up across the State and beyond its confines it is found not to coincide with any parallel of latitude or isothermal line, and not to be entirely dependent either on topography or the physiographic conditions. “If, however, a geological map of the region be examined, the line of demarcation between the two zones will be found to follow the trend of the geologic formations whose outcrops extend in a northeast direction across the State and southward beyond. A coincidence was suggested, and it became more apparent, as the investigations proceeded, that the two classes of angiosperms and gymnosperms were severally identified with certain geological formations, and also that the distribution of many species within each of the zones was capable of being similarly associated, and their limits of being more or less accurately defined. The deciduous zone is roughly located as lying north of a line between Woodbridge and Trenton, and the coniferous zone as being south of a line between Eatontown and Salem. Between these two lines is an area about sixteen miles wide where these zones overlap, which the author calls the “tension zone,” because a constant state of strain or tension in the struggle for existence prevails in it. In the deciduous zone the geological formations are numerous, with various soils and every gradation of topography, and the diversity of trees is great. Its southern line is coterminous with the southern edge of the Triassic formation. The coniferous zone presents but little diversity in geology or topography, and little variety of trees. Its northern border is coterminous with the northern border of Tertiary gravels, sands, and sandy clays. The “tension zone” includes practically the whole of the Cretaceous plastic clays, and the clay-marls and marls.

MINOR PARAGRAPHS.

A conference was appointed, to be held at Wiesbaden, Germany, October 9th and 10th, to promote the formation of an International Federation of Science--a scheme which was referred to in Sir Michael Foster’s presidential address before the British Association. This idea for the establishment of an international association of great learned societies appears, the London Athenæum says, to be the outcome of discussions carried on at Göttingen in 1898. For some time past the Academies of Vienna, Munich, Göttingen, and Leipsic have been federated into an association or “Castell,” each meeting in turn at their respective headquarters to talk over scientific matters of joint interest. At two or three recent meetings questions were brought up, such as antarctic research and the cataloguing of scientific literature, which, besides being of sufficient interacademic value to come before the “Castell,” were of prime importance to English men of science. English delegates were therefore invited to attend, and did so; and out of this invitation has grown a desire for a wider international basis for the association. The adherence of the principal learned societies of the world, including our National Academy, is said to have been secured to the movement.

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The thirteenth season of the Department of Botany at the Marine Biological Laboratory, Woods Holl, Mass., will open July 5th and continue till August 16th. Three laboratory courses are provided, accompanied by lectures, including the subjects of cryptogamic botany, plant physiology, and plant cytology and micro-technique. The principal instructors are Dr. Bradley R. Davis, Mr. George T. Moore, and Dr. Rodney H. True. The department extends a special welcome to investigators, and desires their co-operation in the development of the laboratory. Woods Holl offers great attractions in variety of material and facilities for biological research, and is proposed as an excellent center of resort where the botanists of the country may meet for a few weeks. A six weeks’ course in Nature study, including both animals and plants, and consisting largely of field work, is a new feature offered this year for the first time.

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