SCIENCE NOTES.

New Zealand Mail, Issue 1508, 24 January 1901, Page 60

SCIENCE NOTES.

PHOTOGRAPHY IN NATURAL COLOURS. The problem of how to produce photographs in natural colours has engaged the attention of photographers for upwards of 40 years. Processes have been introduced to notice from time to time, but very few of them have got much beyond the experimental stage. The quest, however, - has never stopped, and there is reason to believe that we are now within measurable distance of the time when photographs in colour will take the place of those in monotone. To illustrate what has been achieved by Mr W. M. Warneuke has brought together in his studio at 4, Uytliswood square, Glasgow, a. collection of portrait, figure and other subjects which have been photographed in natural, tints. Tne colours are pure, and the effects are very fine. The photographs have been produced by thq McDonougli-Joly process, v. Inch is con-. sidered so satisfactory both ailbticbly and commercially that a company is being formed to enable it to be generally employed. In working, a screen, on which parallel lines of red, green and blue are ruled, is placed in contact with an isoch romatic plate, which is exposed and developed in the usual way. - If n col um;d transparency is d-esir/d the pcs - , live is exhibited in conjunction with a screen ruled in the same way as the one which was used in obtaining the negative. If a coloured print is to be p re due ul it is made on printing-out paper ruled in similar manner. One of the most astonishing features of the invention is that if a pho-to.-block prepared with inter u-ntion r f the colour screen is printed with a single ink on a ground bearing the colour lines the resulting picture appears m the natural tints. When the process is perfected it should play an. important j art m illustrative art. “X w ’ RAYS IN OPERATIONS. Before the Hastings Coroner, the inquiry was conducted into the circumstances attending the death of Catherine Fanny Wilson, a widow, aged 68. Evidence bad been given that X-rays were used to locate a -supposed fracture of the thigh, 1 the result of a bicycle accident, and that shortly after an. eruption broke out on the stomach. A letter had been written by deceased in which she alleged “cruel over-exposure of the X-rays/” Five weeks before death she was not of sound mind. Dr H. Roberts, who was called in when the eruption occurred, said that death was due to exhaustion from effects of shock, evidently resulting from the fracture of the thigh and application of the Rontgen rays. The photographer, Mr Blomfield, stated he gave exposures of 35 and 45 minutes each. Dr Lev/is Jones, medical officer in charge of the electrical department of St. Bartholomew’s Hospital, London, said he considered proper exposures had Been made. Some persons were sensitive to X-rays and some ■ were not. ®lt was not known why this was so, but it was believed to be due to the stat : e''of the skin at various times. Some risk from X-ray burns was always present in long exposures. Witness had never heard of a case in which an X-ray burn had caused death. The jury returned the following verdict : —“That deceased met her death from shock and exhaustion following an accident and the effects of the X-rays on a weakened system. No blame attaches to either the medical man or the photographer/’ ANOTHER AMERICAN WONDER. Hundreds of people are said to be visiting a hole in the side of the mountain near Coudersport, Pennsylvania, which must be a delightful place in hot weather. The bole was dug by a man in search of mineral wealth. The farther he dug the colder became the atmosphere. At the depth of 20 feet he was compelled to stop. The peculiarity of this mine is that about May ice begins to form in it and continues to freeze until October. There is no ice in the hole in winter. The warmer the day the more ice there is in the mine. On approaching the opening on a hot day a strong current of cold air is felt. The ice begins to form less than a foot from the top, and coats the sides of the shaft several inches thick. What causes the intense cold and where the air comes from are questions that have not, as yet, been satisfactorily answered. A NOVEL SPEED RECORDER. A simple method of recording the speed of motor cars and other vehicles has been devised by M. L. Gaumont, and accounts of the device appear in “Cosmos” and “La Nature” of November 3. The instrument consists simply of a camera with a double shutter, by which two exposures are made of the same plate, separated by a known interval of time. On developing the photograph two images are obtained of the moving object, and, by measuring the distance between them, the dimensions of the car being supposed known and also measured on the plate, it is easy to calculate the speed of the car at the instant when the photograph wa.s taken. The object is to assist the authorities in regulating the speed of these vehicles and checking furious driving. THE “HUXLEY MEMORIAL.” In the course of his "Huxley Memorial” address, Lord Avesbury said: —Huxley,s Friday evening lectures at the Royal Institution rivalled those of Tyndall in interest and brilliancy; yet he said him sell that at first he had almost every fault a speaker could have. He was one of the foremost of those who brought people to realise that science is of vital importance in their lives; that it is more fascinating than a fairy tale and more thrilling than a novel; and that anyone who neglects to follow tlie triumphant march of discovery, SO inspiring in its moral influence and ifcs revelations of the beauties and wonders of the world, is deliberately rejecting one of

POPULATION OF THE UNITED • STATES. It is officially announced that the total population of the United States for 1900 is 76,295,220 —being an increase of 13,225.464 as compared with 1890. Probablv it is approximately 77 millions. WHY WE ARE RIGHT-HANDED “I venture,” says Sir James Sawyer, in a medical journal, “to suggest that the normal position of the heart is the efficient cause, or, at least, a chief cause, of the prevalent right-handedness. In the earlier days of the human race, man was a fighting animal, a people fighting hand to hand. In such fighting a weapon such as a stick or a sworcl was used. It is ail advantage in so fighting to fight with a stick or with a. sword which can be used bv one arm and hand only; the other arm and hand being used for balance, for defensive covering, or for. offensive seizing. Tbe right hand is preferred for the wielding of the stick or sword, so that the heart may be kept away as far as possible from the assault of an adversary. So arising, righthandedness would thence be transmitted by imitation. It will be found in practice that an excellent way for the acquirement of ambi-dexterity or ‘both-hancled-ness’ is in the learning of left-hand handwriting. Ambi-dexterity would tend to more equal, and therefore the healthy, use of the two sides of the brain. WALL-PAPERS. Colour and surface of walls have much to do with the lighting of a room. Recent experiments have shown the following percentages of reflection for different wall materials—Black velvet, 0.4; black cloth, 1.3; black paper, 4.5; dark blue, 6.5; dark green, 10.1: pale red, 16.2; dark yellow, 20; pale blue, 30;. pale yellow, 40; pale green. 46.5; pale orange, 54.8; pure white, 70; mirror covering, 92 per cent. THE BALLOONING PRIZE. In connection with the International Exposition at Paris, a. number of balloons recently ascended from Vincennes with the object of testing which could remain in the air for the longest period. “La. Nature” gives the following- results:—Count Henri de la Vaulx descended, after a journey lasting 35hr 45min, at Korosfcichew, in Russia, the distance from the startingpoint being kilometres, and the greatest altitude 5700 metres. M. Jacques Balsan descended after a voyage of 27hr smin. having attained a. maximum altitude of 6540 metres, and reached a. distance of 1345 kilometres from the starting-point. M. Jacques Faure descended in Germany, 950 kilometres from, the starting-point* after a journey of 19Kr 24min. Upon these results. and those of previous contests, the grand prize in aeronautics has been awarded to Count Henri de la Vaulx,