The Phonogram, Vol. 1:1 (1891-01)

THE PHONOGRAM. 21 The Phonograph at Clinics. MONG the many uses which have been propos- ed for the phonograph one has been found that is likely to become prac- tical. £ prominent Lon- don hospital surgeon has lately employed the phonograph to record the characteristic changes in voice sounds which mark a variety of diseases. The ex- periments were entirely successful, for the machine reproduced the characteristic vocalization of some diseases with realistic effect. The whoop of the whooping-cough and the intervening cries of the little pa- tient,' and also the hoarse utterances of those suffering from aCute or chronic dis- eases of the throat or lungs were vividly re- produced. This new application of the phonograph to the purposes of diagnostic anc^ chemical instruction will revolutionize chemical teaching in medical colleges, since it will be possible to place a series of cylin- ders iti every medical lecture-room, which would give students a lifelike reproduction of the characteristic sounds of persons suf- fering from the many throat and long dis- upon scientific laws, more immutable than those of the Medes and Persians, and no such damaging charges can be laid at its door as are so often made against the un- scrupulous, irresponsible gas meter. It con- sists of a small glass cell, containing a so- lution in which two zinc plates are im- mersed. A certain proportion of the cur- rent entering the building is diverted through this combination, and an electro- plating action is set up in the cell, zinc being deposited on one plate from the other. Ac- cording to a well-known scientific law, a current of certain strength will deposit just so much zinc in a given time, no more and no less. Therefore, it is easy to see that if the plates are periodically weighed, the. amount of current supplied between the time of weighing can be calculated to a nicety. ^ ^ Edison Dynamos. The electric lighting field Mr. Edison has made peculiarly his own, so much so that, in the popular mind, his work in this direc- tion has become far more prominent than the vast amount he has done in other direc- tions. He was the first to appreciate the - r The Edison Meter. One of the principal difficulties met with at*an early date in the history of commer- cial electric'lighting was the absence of any method of registering in a faithful manner the 'quantity of current supplied to each consumer. Mr. Edison set himself to sup- ply this necessary feature of a central sta- tion system, and thoroughly sifted the sub- ject in his usual painstaking manner. Many experiments were made with all sorts of mechanism, motors, clockwork, electro-mag- nets, springs, heat, electrolysis, electro-dep- osition, etc. Finally,the Edison chemical meter was evolved, and this ingenious piece of apparatus has done its work faithfully for more than eight years. Its action depends ^ importance of making dynamos with mas- sive field magnets. The general principles of the dynamo and its mechanical construc- tion were well understood when Edison commenced his famous experiments with incandescent lighting, but there had been a general tendency to make the field mag- nets of those earlier, crude machines very light, and he radically changed dynamo practice in this respect, as the increased ef- ficiency which he obtained with massive field magnets was at once apparent. He design- ed the first large steam dynamos, and the first experimental one which was built at Menlo Park caused considerable excitement when it brought up to candle-power some seven hundred lamps scattered about the buildings and streets of the village. In 1SS1 he built a dynamo weighing twenty-seven