Al'gust 29, 1890.] 



SCIENCE. 



117 



the error of the control apparatus is probably greater than 

 that of the chronoscope. To obviate this difficulty I make 

 use of a ball held in position by a magnet, and falling from 

 any height up to seven feet, upon the arm of a well-balanced 

 lever, thus securing an instantaneous release. By setting the 

 magnet and ball at difTerent distances we are also enabled to 

 decide whether the error is absolute or relative. It is here 

 necessary to break the current by which the ball falls, and 

 to make the current by which the chronoscope starts at the 

 same moment ; this is effected by a key specially devised for 

 the purpose. The chronoscope possesses a regulation for 

 alternating its rate when too slow or too fast, but I find it 

 most convenient to make sparing use of this, and apply a 

 •correction for each day's determinations as found with the 

 ''fall apparatus." Another form of control msikes use of a 

 falling hammer, the record being also made with a tuning- 

 fork. A recent device of Ewald combines the two methods 

 "by mechanically counting the vibrations of a tuning-fork : a 

 ^ielicate armature is drawn to and released by a magnet with 

 •each vibration of the fork, moving the hand of a dial over 

 one of its divisions as it does so. The fork is vibrating con- 

 -stantly, but the making of the signal sends the current into 

 the " interruption-counter," while the re-acting movement 

 again diverts the current away from it. It will record at 

 the rate of one hundred per second. Galton has constructed 

 for ordinary uses a machine in which the signal is given by 

 the release of a rod or pendulum, and the re-acting move- 

 ment mechanically arrests the fall or swing, a scale of in- 

 terval being determined for the apparatus empirically. San- 

 ford has devised a simple but not expeditious chronoscope, 

 in which the signal and the response separately set in mo- 

 tion two pendulums of slightly different periods, the re-act- 

 ing interval being calculated from the number of oscillations 

 occurring before the two are again in unison. 



The methods of indicating the moment at which the 

 signal appeared and the moment at which the re-acting 

 movement was made are simple. When the record is writ- 

 ten on a rotating surface, a point connected with a magnet, 

 and writing a straight line beneath the vibrations of the 

 fork, writes that line at a different level when the signal is 

 given, and returns to the same level when the re-acting 

 movement is made; or the tuning-fork itself may be made 

 to write at a different level during the interval measured. 

 The arrangement by which the level is changed on the rec- 

 ord, or the hands are set in motion in the chronoscope at 

 the same instant that the stimulus appears, is equally sim- 

 ple. For sound, the noise of the key by which the circuit 

 is made is generally sufficient, or other sound may be pro- 

 duced by bodies falling upon various surfaces and thereby 

 opening or closing a key. For sight, the impression to 

 which a re-action is to be made may be concealed behind a 

 •screen, and the drawing away of this screen at the same 

 time makes or breaks an electric circuit. Frequently the 

 Te-actor sits in the dark, and the impression becomes visible 

 only when an electric spark appears, or the spark itself may 

 be the stimulus. For touch, temperature, and taste, a typi- 

 cal device is that of Vintschgau, in which the end of a rod 

 touches the sensitive surface, and the pressure so exerted 

 makes a contact with a delicate metallic blade inserted in 

 the same apparatus. For smell, the movement by which 

 the odor is set free is similarly utilized. The re-acting 

 movement is usually that of pressing an ordinary telegraphic 

 key. Devices have been constructed by which movements 

 of the foot, of the jaw, of the voice and lip, may be similarly 

 noted. For more detailed descriptions consult the references 

 under this head at the end, Joseph Jastrow, 



[To be continued.] 



In the Atlantic for September Mr. Justin Winsor considers 

 the " Perils of Historical Narrative," Mr. J. Franklin Jameson 

 contributes a paper on " Modern European Historiography," and 

 Mr. Fiske adds an article on the " Disasters of 1780." These 

 three papers furnish the solid reading of the number. 



PROFESSOR A. GRAHAM BELL'S STUDIES ON 

 THE DEAF. 



In the year 1888 the Eoyal Commission appointed by the 

 British Government to inquire into the question of the care 

 and education of the deaf called to their aid Dr. E. M. Gal- 

 laudet, the distinguished president of the National College at 

 Washington, and later Professor A. Graham Bell, whose long 

 interest in the deaf qualified him more thau any other pub- 

 lic man in America, outside those directly engaged in the 

 work of instruction, to speak with some degree of authority 

 on the questions presented to him. The information pre- 

 sfnted by Professor Bell has been published in pamphlet 

 form, entitled "Facts and Opinions," and contains a great 

 variety of facts concerning visible speech, heredity, day 

 schools, articulaticm, and kindred subjects. The Eoyal Com- 

 mission has recently completed its investigations, and re- 

 ported to Parliament the results of its work. I mention the 

 report right here, to draw attention to another of those sin- 

 gular conclusions which have characterized the opinions of 

 men of unquestioned learning and intelligence, when under- 

 taking to speak officially concerning the deaf. In paragraph 

 398 of this report we find this extraordinary statement, 

 " The want of exercise of the lungs and throat on the part 

 of pupils taught by the manual method is apt to produce 

 chilblains." Two members of the Commission had the good 

 sense to dissent from this paragraph, and oificially to pro- 

 nounce it "quite absurd." 



It is impossible within the limits of this article to discuss 

 seriatim the several subjects upon which Professor Bell has 

 addressed the public, and I am therefore compelled to make 

 a selection from those studies with which his name has be- 

 come most closely associated, and from these it will be easily 

 possible to infer the value of what he has done for the deaf. 

 It is also necessary to add, that, in the friendly contention 

 for methods aroused by Professor Bell's long indictment of 

 our American schools, there is on our part a ready recogni- 

 tion of the honesty and zeal whicb has inspired him; and if 

 we speak plainly on the studies which he has given to the 

 public, we ask for ourselves a recognition of the same sin- 

 cerity, something of that same chevalier spirit with which he 

 has carried his lance against us. 



The first measure for the education of the deaf with which 

 Professor Bell became identified was "visible speech." This 

 is a system of universal alphabetics, originated by A. Melville 

 Bell, and was introdviced into the United States nearly 

 twenty years ago. The first exposition of this system of 

 vocal physiology in the city of Boston created quite a sensa- 

 tion in literary circles. The extraordinary statement, during 

 the first few months of ti-ial, that "adult deaf-mutes had 

 acquired all the sounds of the English language in ten les- 

 sons" (Report Massachusetts Board of Education, 1871-1873), 

 drew, at once, the attention of all those interested in the 

 deaf to this new device. From the report already referred 

 to, and from that of the succeeding year, we find that " the 

 effects produced by this new system are in the highest de- 

 gree remarkable — even miraculous;" and again, "Perfect 

 and pleasing articulation is certain." To this last claim, it 

 is enough to say that to day there is not a reputable teacher 

 in the United States who makes any approximation to so 

 rash a claim. In view of all that was claimed for visible 

 speech, it is not surprising that it soon became among us a 



