SCIENCE AND DISCOVERY.

Taranaki Daily News, Volume LII, Issue 395, 21 May 1910, Page 10

SCIENCE AND DISCOVERY.

WILD BEAST TRAINING. "The entire art of the trainers of wild animals," writes Pierre Hachet-Souplet, in his investigation into the psychology of animals, ''consists in their availing themselves of the fear of their pupils, and in driving them wherever they wish to. As soon as one opens the cage of a wild animal, it flees to the opposite side. If one does not .proceed farther, it remains in a crouching posture, and places itself upon the defensive. If one approaches the animal with threatening mien, it attempts to get away. It is necessary only to give it a path oi escape, otherwise one will be attacked. One follows it thus from one comer to the other; if it finds an obstacle to its flight, it without ado vaults over it. Animal trainers have no other secrets. Their art consists mainly in making these procedures dramatic, in that they make it appear, as far as possible, as if they were conquering the will of the animal; thus —for sake of the impression—they hesitate for a moment before causing the animal to spring over a barrier, iby a slight forward motion on their own part; the whole thing is made more vivid (by the cracking of whips.'

A NEW THERMOMETER,

A clinical thermometer, which automatically registers every. fraction of. a degree, in an invalid's changing temperature, has just 'been perfected by Professor Hugh L. Callendar, of the Imperial College of Science, Kensington (London). The accurate study of the variations in temperature the human body undergoes, either in sickness or in health, during the cycle of the twentyfour hours has hitherto been impossible on account of the lack of a sufficientlyreliable recording instrument. Professor Calendar's apparatus does away with this difficulty, and opens to research 'workers an entirely new and unexplored field. The thermometer itself consists of a very fine flattened coil of platinum wire. l-250th of an inch in diameter, wound on a thin strip of celluloid film. This film is then covered, for the purposes of insulation, by a second thin film of celluloid. The ends of the plati-j num wire are connected with ordinary j copper flexible electric light leads. An extremely sensitive galvanometer, which will instantly record any increase or de-1 crease in the amount of electric current passing is let into the circuit. The leads . •then (pass to an electric recorder, on which the extent of the variations in the current passing are noted by an up- j ward or downward swing of an ink-tip- ] ped pointer travelling on a continuously- j revolving drum or cylinder. The principal of the thermometer is that any change in temperature- of the coil of platinum wire will 'vaTy the amount of current which can pass through it, this change being determined by the galvanometer, and recorded on the revolving drum. In use, the thermometer in its insulating celluloid case is placed in the armpit, being kept in position by a bandage, 'which passes over the opposite shoulder. The arm is also bandaged to the side, so that the thermometer is protected from all influence on the outside air. The apparatus, which it is expected will be used chiefly in hospitals, in diseases such as typhoid and pneumonia, is made by the Scientific Instrument Company, of Cambridge. MISCROSCOPE'S POWER. Workers with the microscope are olten tantalised by the knowledge that there are interesting objects far beyond the powers of their best instruments. It has been recognised that it is not possible to study objects less than half a micron in diameter. A micron, it may be noted, is 1.100 of a millimetre, which is itself about 1.25 in. Thus the smallest miscroscopic object is about l-50,000in in diameter. By means of what is known as the ultra-miscroscope objects of l-50th, the size of the above can be distinguished. The ultra-miscroscope differs from the ordinary miscroscope only in the method by which the object is illuminated. In the latter very small objects; are, so to speak, drowned in the brilliancy of the lighting; in the former the light falls on these, leaving the rest to j obscurity. The difference is best illustrated by. the com pari son of a room full of sunlight, and a darkened room, through which a single beam of light is allowed to pass. Iti tlie latter we seei clearly the dust particles in the air, I which are quite invisible in the former. In the ultra-miscroscope the necessary I darkened chamber 'with the single beam of light is secured ibv « simple system j of prisms and lenses.