The Production of Sound by Radiant Energy

iuitcrpr/iino leAwosow" I htatce In a paper read b)efore the Amierican Asscciation for preltio of lteMiriosey5e.Inthatartcle the Advancement of Scewnce, last August, 1 dtcs-ribecA we gave very strn lusrtosofte", iseprsen-certain exp)eriments mnade l)v Mr. Sumnier 'faintcr and ta/ionis" referred to, buit the pa.per wvas writteni somei myself which had r-esulted in the conistruction of a -I'Iho- years in advance of the presenit developments, which ofihone," or apparatus for thle production of s:ound by i'ght;-,+ andI it will be my object to-dlay to describe the hiave miadle the case mutchi stroniger.Th'le disputed pro-ress we have madle in the investigation of p)hr,toresoutin ofthe"I~oura scle ws ten qote as phonic phienomena sinlce the (laste of this comniunica-- instanceofan two ~~~~~~~tion.aiinsaceoai objective giving to(listinict resolui- In my Bloston pap r thle (liscovery was announced that tionis of ani object, onle of which was clearly an erronie-thiin dlisks of' very many (lif'ferenit substances e:i//dl-t Otis onle, btit whio Nvould have theni aniticip)ated that SOlUlti1v when exp)osed to the action of a rapidly -aiter- ruptedl beam of stinliglit.h'le gra variety ofinatcrial the sheruls on ngu/'Iui hc ehv o o used in these exp)erin.ents1kd mie to bt-l:tve that soni,r_ miany) years religiotisly regarded as the true uiltimiate ousness uinder such circumstances would be foundI to) be resolution o tht(itm wudpoetob nilD a genlerail property of all matter.resoutioi oftha diaoiii woild roveto e ai ill- At that t'ime we hadl failed to ob)tain auilible ef-fects from sion ?Wh'Iile to make the case miore complicated, Pro-masse:s of thie v-arious substances wshich be:came sonocruus fessor E. Abbe states that "1whiile it is not miy op)inion in'the condlition of thiin (Iiaphragms, but this faiilure was txp)lained upon the suppositin that the miolecular thatthe Jn.eula,unvalv is ompsed f sherues,disturbanice p)rcdIucedl by the lig,ht was chiiefly a surface yet even if sttchi shiould exist, they' wvoildI not have a azction, antI that tunder the circumstances of the experi- different effect."~~~~~~~nints, the vibration hadl to be, tranismiitted throughi the mass of the substance in or(ler to affect the ear.It was Thius " The Afs i/e'rpr/i/n of /ic JJie1ros0Yop' therefore supposed that, if we couldI lead to the car air ttn(er crtan coditins,is no myth, btit an admiitted that was dlirectly in contact w~ith thet illuminated surface, facti;ler weltiicomedithenste Imrviflft hc hl loudler souni(ls might be obtained, and solid mrasses b- at least partially remedy the evil.Th'le high angle t ea ooosa hnda rgn.'h is experiments niiarle to verify this hypothecsis l)ointe(l to- objectives of the p)resen3t, althiouigh far fromi l)erfect, wards success.A beami of sunlig-hk was focussezd into give great hiope for the ftitttre, and( 'ye trace in one end( of an optn 'tube, the ear being placedI at the 9 towlich efeeiie las een othier endl.Upon interrupting the beam, a clear, musical Plrofessor Smiith's wvork,t hc eernehsbe tone w~as heard, the pitch of wh,xiich depended upon thle md,the advent of a highier intelligence among" freqjuency of the interruption of the lig,ht and 10IodthSS ,Microscopical workers.'1'hiis new spirit of p)rogress U)f h aeilcmoigtetle At this stage our experimients were interrup)te(l.as cir- is wvell (describ)e(l by D)r.Beale whieni hie says.the ctimstances called mie to Europe.Microscopist, like thle Astronomer, is ever l'onging \While in Paris a new formi of the experiment ocetiriied to my1 mind.w hich Would niot onlyv enlable tis to investi- to get a little beyond the l)oint at which hie hias gaetesud rdielbmae,btwodalol)- already arrived.Elach iie' fact gained by researchi miit us to te-st thle more general prop) Sitio11 that stzruous- seemis btit to ind(icate the existence of miore andI It"S Wllllr/ic heii?I/it ence of ui/tcnni/h.':/lQi/h.is, ~tiprop.e,/I;f common to t/i ma//er.miore iml)ortant thingrs beyond.Limit is reached ThI utnet etetd -a ob lIcdi h n ani(I theni surmiounted, l)ut sooni a nlew limiit seems to tenior of a transp)arent vessel.madle of some material rise fromi the miists in the dlistance towards which the which (like glass) is transparent to lighit, but p)ractically opaqlue to soltind.worker is impelled by new hop)es anii( (lesircs.It is Und(er such circumstances the light couldi get in, but this never-halting progress whlich distinguiishes scieni-the sotindI p)roduced by the vibration of the substance othe kid o inuir, anI jartculrly couldi not (,et out.The audible effects coul!d be situd:ed tific from every' l~~~~~~~~)y placing the ear in commiunication wvithi thec interior of m;icroscol)ical investigation, for it cani never be corn-the vessel by mieanis of a heatingr ttilv pletedl.It deals with the illimiitable.The bouindlaries Some preliminary experiments wvere ma,le in Paris to of today' re fond toave vnishe to-mrrow,antItest thiis idlea, and( the i esults wecre so promising that they *\vere communicated to the Frenchi Academy on thbe I ith the eyes and understanding begini to p)enetrate inito of October, I 88o, in the niote readl for mie by Mr. Antoine regios ~vich ut ashor tm beoehd encn-Breguet.4Shiortly afterwardIs I wrote to 'Mr.Tainiter, suggresting, that he shouldi carry on the investigation in sidered far beyond the range of p)ossible investigation.Ameic, as circumstances prevcentedl mie fromi doing so myself in Eturope.As these exp)crinients seetil to~have ___________ t~~~~~~ormiiedthe commiion startingy point for a stries of ind(e- pendent researches of the mlost imiporta-nt chiaracter.CONDcTIIILTY O GLSS OR i~(ALvNic RRNT.carried oni simultaneously, in America by M\r.Tlainter, -According so A. Sewarz, if two platinium wires are inter- posed in the same circuit, thec one passing thiroughi the free *A Piper readi before the 'Nationd A.ad'_my of Arti and ccc air wlhile the othier lies betwveen two glass plates, or is IApil z i88z.melted into a thick capillary tuibe, at a certain temiperature t Proccedimns of American Ass ciation for the Advancemient of Science. of the tube the former glows brilliantly, wlhiIl the second Ag 7 So e,an mrcnJuu fSine o.x,pIf thegass, beonies lcated te forme lourndl of the Amneric.inEictrirc-LI Socicty, VoLii.Pt.it3; Juitruil of the remains dark.Iftegasbcmshaeh