SCIENCE NOTES.

Otago Witness, Issue 2010, 1 September 1892, Page 44

SCIENCE NOTES.

— Milling machines and cutters are rapidly supplanting the laborious processes at the vice, and with the slotting and planing machines of the practical engineer work that was done a year or two ago at the slotting and planing machines and afterwards filed, is now designed so that it can be finished by milling cutters alone, being afterwards highly polished by the aid of buffing wheels and belts. Double eyes and other fitting parts of machinery which were formerly painstakingly filed up at the vice are now turned out at the milling machine by skilled labourers, at about four-sevenths of I the wage of mechanics. — Professor Houston in his Brooklyn address made five interesting prophecies on the future of electricity— namely : That electricity would be produced directly from coal ; that the steam engine would be entirely replaced by , the electric motor ; that as rial navigation would be effected by electricity ; that electric light would be produced without heat, and that' electricity would be applied to the curing of diseases and the prolongation of life. — The curious fact is now pretty well realised (writes a B.Sc. in the Adelaide Observer) that green plants require a supply of oxygen for respiration just as much as animals, and that the operation of the oxygen in the plant is ' ultimately to convert some of its substance into water and carbonic dioxide, just as the oxygen taken into the lungs and then into the blood is finally given out at the lungs in water and carbonic dioxide. But in green plants the carbonic dioxide which is produced as a waste product of respiration is an important constituent of plant food, which, so to speak, is digested in the leaves under the influence of light. But with fungi the case is different, as they have no such power of using carbonic dioxide as a food supply, and on account of this difference special interest attaches to the processes of respiration and nutrition in the iichenp, which are now known to be fungi and green algae united and mixed up in a most thorough partnership for the benefit of both, one result being that the partnewhip is much hardier than either member of it could be alone. Some recent experiments prove this well. Ordinary above 95deg Fahr ; 21 hours at 113deg kills them, and a few minutes at 120deg; but some lichens will' stand 15 hours at 120 dee before they die outright, and can even survive five hours at 140deg. Even at this temperature it is the alga which is affected ; the green plants cannot stand a temperature in which much fungus is still apparently healthy. On the other hand, the lichens can stand a most fierce colJ far beyond the endurance of ordinary plants. — " The Pupil of the Eye as a Factor in Expression" is the title of a clever paper by Dr Samuel Wilks in the Magazine of Art. The changes of the eye with light, but more particularly with feeling, are discussed, and the conclusions drawn are as follows :— " My own belief is that much of the expression of the eye, indicative of the passions of the mind, referred to by novelists and poets, is dependent on the size of the pupil ; that in anger of various degrees and kinds the pupil is contracted, whereas in somnambulism, ecßtacy, and their various modifications, as well as in suoh mental moods where the senses are hushed, and serenity, benevolence, and the pure passion of love prevails, the pupils are dilated. If this be so, the eye is not only one of the gateways of knowledge,

but is a portal through which the working of the brain becomes manifest, and further proves, in the language of Scripture, " that the lamp of the body is the eye."

— A French paper reports that the microphone has been successfully used in St. Petersburg in a case of suspended animation, where the patient was given up for dead. As a last resort the physician applied a microphone to the region of the heart, and was enabled by this instrument to hear a faint beating, which proved that life was not extinct. Everything was done" otresuscitate the patient, who Bhortly after recovered consciousness.

— Instantaneous photographs of the motion of the lipsjn speaking^have now been successfully combined in an instrument designed to exhibit the movements in sequence, and enable deaf mutes to understand what was originally said. M. Dumen'y, the inventor, calls the instrument the phonoscope, and it must certainly be considered one of the most carious and ingenious of modern inventions. The changes of the lips in speaking, it is said, are so rapid that 15 photographs a second are required to give a good result. Moreover, several sets of images for the same phase are taken, so that nothing essential shall be omitted. The whole bead and, bust of the speaker is photographed, so as to get the benefit of the expression. In the phonoscope the positives are arranged round the periphery of a disc, which is rapidly turned by a handle. A second slide, having a single window in it just opposite the plates, is also rotated by the same handle, but at a much higher speed than the other. A beam of sunlight illuminates the plates from behind ; and the observer, looking into the apparatus, sees them pass his eyes one after another in such rapid succession as to produce the effect of a single image endowed with animation. To this end at least 10 or 12 must pass the retina in a second.

— The creeping of rails has attracted some attention of late, and while we do not attempt to explain it, we offer a point on the fact that on lines running north and south the western rail " creeps " faster than the eastern rail ; that is, this strange movement of the rail towards the south is more marked in one rail than the other on the same track. Furthermore, it has been noticed that on such a line the eastern rails wear out the fastest. Both of these points, we think, can be explained by the motion of the earth as it turns from the west towards the east. Motion tends, to overcome gravitation. A rapid skater flies over the thin ice without breaking through, and a train at high speed has been known to leap a broken bridge unharmed. Momentum overcomes gravitation, and the greater the speed the less the weight on the rails. Everything that has free motion is dragged after the whirling globe; every wind that blows, and every tide that moves, feels the influence, and our train going north or south is pulled over toward the east, and naturally presses the eastern -rail most heavily. The western rail 1 being' relieved of its share of weight, more freely and quickly. It is also noticed that the wheels that run on the' eastern rail wear out first, and we can but think that this earth motion is the true cause. The practical side of this is, that the eastern rail and wheel should be stronger. — Scientific American.

— A great feat in the electrical transmission of power is to be undertaken in Southern California, where a contract has been closed for transmitting 1000-horse power a distance of 15 to 30 mile 3 in the neighbourhood of Pomona. — The longest sleep on record- is reported from a German Hospital, where a miner has been fast asleep for nearly five months in spiie of continual efforts to waken him. The body of the man shows the rigidity of catelapsy r • but otherwise the appearances are those of ordinary health. The only food he has taken during that time has been about two quarts of milk a day literally poured into him, and on wakening he would take nothing else. He is quite unaware of the length of time he has spent in unconsciousness. The little that is required to keep mere life going apart; from activity is well shown by this case and the recent performances of fasting men, and one is forced to take account of quality in' estimating the value of a life. One half hour of alert activity is worth more than endless centuries of cataleptic sleep, and an active man, thoughTcut off at 50, may have enjoyed far more actual living* than a dullard that lives to 100.