The New York Herald Newspaper, September 7, 1856, Page 2

| TE StVENTIFIC CONGRESS. Acerjean Ascociation for the Advancement | of Science, THE YELLOW FEVER: Interesting Reports on Electricity, Expe” ments om | Visual Direction, Meteorology, Typhoons and | Cyclones, Whirlwinds and ‘ay Early Voy- ages of (he Scandinavians to America. THE CLOSE OF THE PROCEEDINGS, ke., Xe., ko. Our Special Correspondence, Away, Aug. 23—7. M, cir work yesterday. In tho Geo which had been on the programme for ys, and which did mot seem t> be very appe! several d zing, were vead. Que of these, I ought to say, was a re- view of a geological map of the United States, pud- lished in France by one Jules Mar: who, it seems, has blundered terribly, for the which Mr. Secret: Bake has been impelled to chastise him, Geoiogists aud otbers will therefore take notice that they ought not to buy Mr. Jules Marcou’s map; aud o} reach subscribers will be so good as to Gnd out this Mr. Marcou, and ask thim what «id he mean by traducing the ge al cha- racter of our country’ Let him be told his tact, as be would say himeelf. comers, Notice, Tbeg of you, Prot. Alexan. 1 he developed yesterday in the Senate He supposes their luminosity to arise from Prof. Alexander, that spare, cadaverous, very & man, {s certainly one of the boldest of observers aud theorists in this tection, as wel of the most eloquent epeak- ers. Prof. Pi Ukemed bim, the other day, to Kepler, and raid that he would have been a Kepler if s new theo Chamber. the electricity cf the sua. all NEW YORK HERALD, SUNDAY, SEPTEMBER 7, 1856. nn TSC SSS Se Ue SE RR nnn RSC nn ERI nn nn ee ee ey a — on name, suse-canEnEE. . ~etmmemeemmremmenne duced by the which all the worl” met and nominal To day, the General Session 4 went, <4 olticers. THE DUDLEY OBSERVATORY. acon Mr. bverett inaugurated the Dudley Ob- | wit ag oration whic, I will make bold to say, of bis noblest efurts. There are very few meu in country Who could have risen to such a height. By nea, you will have it in This after servator we time you receive these | print, oud T ueed therefore say no nore | ’ peed | spend time ia commenting upoa the un- | parnileled hberality of Mrs. Gudley, who has added to ber former donations « further gift’ of Afty thoasand dolars to the Observatory. 1am not informed as to the extent of the laay’s fortase, uor can I say whether aay young relatives are eo fortanate as to be deprived of the lerppiation to jdleness And uselessuess which the posses- sion of this money might have offered tuem — But most certainly history does not coutain another instance of equal tiverality Go the part of a lady, When her letter was read by Judge Harris there was @ goed deal of ap- plause; bot when Professor Agassig sprang up, and Waving Lis bat, called for ** three times three,”’ and one more’? for Mrs, Dadley, the noise was deafening, Such enthusiasm | have rarely witnessed before. CONCLUSION, This Inst inaugura‘ion conciudea my labors here. I mj s4y, ip closing, that tois has beea the most imgor- ant mecvng the association has ever held. There were more mewbers in attendance, and more and better pr pers read than on any former occasion In Ast be report of G . the sketch of methods by he ingenious theories of Alexander, and the moctesé statements of Peiers: in Geolegy, the valuable reports of Hall, Rogers, Daw+on, Schott, Ke , and tue eimiradle generalizations ‘of Dana; ie Physies, the papers of Hears on acoustics and electricity; the results of the Coast Su vey, as presented by Prof Bache; the brilliant and nove! papers on zooiegy wat pacaral history, which we owe to the genius of Agass’z, are only & fow of tue more exsel- lent productions of this meeting of the .issociation, Shoule it aue as it has begow, the country will soor inoeed have cause to be proud of I trust that you will not repent the liberal manner ia which you have devoted space to the long pspers which Dave been read. Though they may seem tedious to some of " re are thousands te whom they will prove resting and valuable, If there exists auy work tn which go much learaing and science ts contained a3 may be found im the last ten days’ issues of the Hxmarn, it has not been my fortune to fail in it. iw on the other hand, fami th that the gentlemen for whose credit you have done so much—some of wtom were ro doubt perties to the foolish attempt to muzzle the prewe made at the beginning of the procseaings—will learn from the fact to understand and appreciate news papers # hitle better in future. Ia conclusion, can only eay that 1 re:arn thanks to Dr. Armsby, Thomas W. Olcott, Fsq., and Mr. Fre terick Seward, of the Albay Eventny Journal, for assistance aut civilities tendered to me in the discharge of my daty. It would have been # duty a3 well as pleasure to mo to Kepler bad net been. The compliment was not so far more exaggerated, or so much on the mutual admiration principle as you m’ght imagine. Since we have been here Prof. Alexander bas presented papers on the moon, ou ‘the asteroids, on the nebular hypothesis and on comets, fan¢ all have been the best papers presented om these subjects respectively. Even Mitchell of Cincinnati, has almost been left in the back ground, though he is, proba- Diy, the greater astronomer. Prof. Peters, the Dane, who, with Dr. Gould, is to have the management and use for the present of the Glcott Meridian Circle, bas already read one paper on his owo comet, and was to have read nother this merping, on two of the older comets, But his cuties in connection with the OSservatory, oblige him to absent himself, so the paper remains over till next year. Another paver, which also remains over, is ove by Dr. Brunnow, of Anapa, on the asteroids. Tnis would have been a useful and interesting communication, and I therefore zend you an ab=tract of it for padlica:ion. A METKOR. Prof. Olmstead, of New Haven, presented a paper om « meteor, which appeared on the Sth of July Jest, and took that occasion to review the subject of meteorology generally. You have in the report asketch of his remarks, which I think you will du: in teresting. it has always seeme! to me singular, that considering the vumber of acrolites which {all on the earth—two per day, in round np ag to Humboldt—so few oud occur. ‘9 uoabt the proportion of unoccupied space to space tat 13 o pied is enormous; bat, on the other haud, I believe th ig but one well authenticated case of loss of life in modera times by the fail of “thenderboit,”’ which was that of @pricet in Italy, which occurret ip the last eantery. Professor Olmsted was rey a Mr. Vaughan, who, seemingly, bas mistaken the Asrociation for an cleme: tary school of ecieuce, an¢ has come here to be elu: THE YELLOW FEVER, In another portion of thus paper you wil! God a sketch of Dr. Webster's remarke on the w fever at Ports- mouth, viewed in connection with atmospueric phenome- ma. Dr. Webster exhibited a map o2 which certain lines, gracuated according toa given scale, indicated the state of the atmosphere, that of the temperature, ano the ex- tent of mortality prevailing at the time. Dr. Webster @id not claim, nor do 1 suppose that any prec Jawa can be evolved trom the facts he record @t the same tme, now that some people are afraid of yellow fever in New York, it may be weil Yo mention that he found the mortality to correspond in A measure with the temperature—tbat is to say, 1b was r toe fw Beaviest on che poten tau. P Wak Riaost always prows <= Gea by a0 increase in tne atmospheric pressure. { refer ou w the brief abstract of Dr. Webster's r:marks for information. ELECTRICITY. A most important paper was read yesterday by Prof. Henry, of the Smitheonian, on the phenomena of the dis- charge of animal electricity. You bave, 1 presume, pad Mshed it entire; as, like Prof. Henry's former paper, it contains much valuale ioformation for ouilders and others. There is another reasoa why it should see the light at the present time. Some o” tho most eminent men of science in Europe are now engaged in investiga ting the very same electrical phenomena; they wil! ao doubt come to the same conclusion as the Smitnsoniea Professor; it ie well iat we be uot accused of stealing ‘tbeir thunder. 1 STERKY BUST. Several papers have been read by this gentleman during the session; you have published abstracts of ihe chief ones amor.g them. the Association meets next year I pecessarily Ggure as one well to state he lee nt, and pupil of oar venerable 4i liman. When Sir Wm Logan undertook the geological gurvey of Canada he was anxious to obtain the assistance of @ fret rate man, who was a native of the continent; on the recommendation of his advisers here he secared the services of Mr. Hunt, who became, and hat erer siace continued to be, attached to the earvey, He has written largely in Silliman's Journal, the Loadon Pnilosophical ‘ other scientific periodisals, on subjects connected with bis own peculiar labors, and also on mineral chemistry, and has had the satisfaction of seeing Ris chemical theories sustained by the bighest authori ties on both sides the ocean. Mr. Hiant went to Paris as one of the Commissioners of the Exhibition, was one of the international jury, and received from the Emperor mative of Connecti the ribbon of the Legion of Honor, which he wears. He has lately been appoinied to a professorship ia the Cai ‘Versite Laval, at Quebec. mores I will only jost draw attention to Mr. Redfeld’s papers on storms and typhoons. They were heard with tt greatest atitention Uy the mathematicians and physci t Qnd were quite worthy o” the reputation of the emineut savant who delivered them. ETILNOLOGY This, a# you are aware, is Professor Agassiz’ section but, unbappily for its interest, he announced privately yesterday that be must withdraw and coilect bis thoughts the oration he was to deliver on the inanguratioa of pee mag Hall. The heat and burden of the day were, borne by l'rof Wilson, of Canada, who made a to prove that the analogies discovered between some the arts of the American indians and those of certaia eborigina! European nations ¢id hot necessarily imply io tercourse between the two bot might be regarded af io Gications of haman instinet The Profesor toox oocation to declare that be was of the opinion that the human fr» ‘was one and indivisinie. Unlike some of his confrere., however, he did not foreibly bring science into collision with revelation, and then stultify the latter or deny the former, in order to preserve an of harmoay between them. He wisely took the when ‘we found a discrepancy between the two, ths proper Courre to pursue was to prosecute our investigations vi Wie = and honesty, in the hope that greater know- woul to @ reconciliation, apd in the meantine to hold our judgment in ee.’ I presume that feesor Wilson is aclergyman. 1 wish all of bis cloth fs rensible an’ enlightened. In the absence of Agasstz RO one took bim w Remarks were made by Professor Anderson, of [otalo, But they wore more of en oratorical ‘than a ecientide ch Dr. Gi»bon, Prof. Baldeman and others, mingled in the (iscussion, without, however eliciting avy new facta of importance MORM RENIC TRACES Dr. Hamlin, of Maine, read anotoer paper on the Soan dinavians, which was Ln A and instractive. Tou have laid it betore your readers. There is nothing, Ithi Which ought to excite more interest in connection American arch than these confused traces of events, so nearly bidden by the dark waver of tme. No one who bas read Longfellow’s “Speak, speak, thou foar ful guest |” can fail to be struck with them, and to desire © know more, if more can be discovered. A complime xt is due to Dr. Hamlin for the light be has thrown on the fubject. He i @ young man of great promise. PROPRSOR SUTCHRE, OF CINCINNATI Print, I beg, the accompanying memoranda of astro Bomical processes by Professor Mitchel, of Cincionati. Not becaure they will intesest your readers at large, bit because they will netroct astronomers throughout the World. T need not tel) you that Professor Mitchel “Is roal ly one of the *most remarkable men of the country—to ure & pbrase which harie alune compels me to employ. A pupil of the Weet Point Academy, he left that ins'itotion with bigh honor, and besame aa astronomical student under Airy, the astronomer royal of Eng and. After traveling through the Continent he re terned home, ani. by bis onaided efforte and great ‘energy, acvually perm wied the people of Cincinaati—that city, whore people are supposed to think of nothing bat 19 subseribe the money neressary for an observa: and a complete tet of admirable instruments That | Consider an immense triumph. Mitchel is a hort, wr with hard feataros iron gray bait, He ie a really’ a great aetronomer, and must not on . be judged by bis populat book on the runjact ol aa tronomy. THR INATOURATION ‘This ceremony, Of which sou bave @ full report els» where et rd afternoon, and weat off re. hen Pema 00 > learn that they ent thre ‘Agassiz waa, of course, the lion of the oer asion his pees fe ad Reautifal idea that of his, that the tour types of the animal kingdom are the four tunes on which +g? plnys the hermonies that are realized nereated beings. baw been the rerions clergy were funny. Dr. Cox, especially, kept the audience Jn roars of levy Io the evening there was a party at the Patroon’s, to thank the Local Committee, had they earned asy ciaimto my thanks; but pow that the work is over, ! have no scruple in saying that the executive agent of’ that body, Mr. Wooiworth, not only venied me the facilities which it was in gis power to have aflorded, batgo far as in him lay seemed to seek to throw obstacles in the way of the prees generally. Seventh Day’s Proceedings. MORNING—GENERAL SESSION. Aipany, Aug. 27, 1856. Prof. Fart in the enair, The usual list of members was read, and they were all admitted. ‘The Standing Committee recommended that the General Session alone ebould meet to morrow. Carried. That the Commitive on Pisciculture should be dis- charged, while the others were retained in existence. Carried. ‘That the Medical Association should be invited te their next meeting. Carried. In reference to the letter of Mayor Wood, of New York, the Standing Comm ttee recommended the passage of the following resolutions, which were accordingly put and carried unanimously — Resolved, that the advancement of science, which forms the great object of this Association, requires, also the establisl: Ihent of wnlversities where all branches of human kunwledge tay be pursued under cminent professors to their last de- velopem: Resolved, That the eat tution in au part ¢ Jeet of the highest vir judgment, jud!ctous effort made for the accom k will reeeive our hearty pendator “Resolved. Thi iderer the recommendation before us as such an effort as is referred ution. Tue auditors A had examined the gto be heard on the sub e had been dealt with woiai’| plain bis views, when The Crain put the motion whether Dr. Hare showlt be heard. Motion lost. ‘A motion was then made to adjourn, (Dr. Hare still epeaking,) which Was carried, and the meci.ng atjouraed into sectors. GEOLOGICAL SECTION. of, Daxa ip the cbair. Free axe uo busiaves of public interest done here this mncwing. ‘Tiree papere were read, pamely: 1._A Review of a Portion of the Reeen! Geol the Uniied tates, published in Europe by J by Wiliam P. Bleke. ‘2. On the Carboniferous Limestone of the Mississippi Valley: by James Hall $. Observations on the Coal Fields of Iiljacis: by R. P. Stevens. Afier debate on these the section adjourned. PHYSICAL SECTION. Prof Gritmrm iu the chair. The following papere were read by Prof. Purxcr:— J. Morpbologien! Inscuseion of the Laws of Contra! forces. 2. Motion of a Mody upon a Solid of Rerolation, when tbe force is directed towards a potat upon the axis. comers. Prof. Srevnes Avexanpee then read a paper on the Puy. ficat Peculiarities of Comets, of which the substiace war as follows —He first remarked upon the c! of (he impencerabie substances, and drew the qoaciuston that, as the eue is very bot, on! being brig ht, and also now ap nee to be magnetic, be murt also be Inghiy electritie found in this electricity the canse of the repu' energy which Bessell and Gauss have shen to be neces sary to account for the form of the comet's bead, The ta Was regarded as matter croticually thrown of by clev- trical repulsion. The curvatare of the tail was accounted for by the change in the direction of the comet's motion while the tail was developad, The elongation and subse quent rupture of Bicla’s comet was referred to an \ntense indvetion; the rupture occurring, of course, in the region of inmost feevle cohemon. y from the san, An arca of cometary matter, how remained, through whieh discharges of electricity must have taken place, as the two pertions thas ed become vupequally electrided, sometimes rendering the one portion of the comet the more conspicuous abd sometimes the otb served. These ciacharges su%equ mtly ruptured and the comet divided into two, which have sloce re- turned separate. The fullowing papers wore then read in their order — an On the Abbreviation of Scientific Titles: by Lieut. Nt 2. A eimple method of correcting the common nautica! hod of “Double Altitades’’ of the San Moon, or a Pie bet, for the chanye of decination between the observa tions: by W. Ghar vxwer 2 Note on the Rotation of a Rigid Body: by J. B. Cunn iM AM. 4. On the Interpretation of Some Ca: metsic Ditcontinuity : by J. B. Caran A WONUERECL METEOR. Prof. D. (naerep, of New Haven, then read a paper on the Miseiesippi Meteor of July 8, 1866, of which the fol lowieg was the substance:— This extraordinary meteor, which appeared in the State of Missiesippi Joly 8, 1866, be regarded as one of the most extraordinary meteors on record, Deing described os shining with great brilliancy im the broat | ght of day, and of an apparent diameter as large as the sup. He had seen among various newspapers statements two accounts which appeared to be very reliabie—the one from Pro fessor E T, of the University of Mississippi; the other by Mr. Macready, of Memphis. The Professor remarked that the testimony of jadi « was eqraily valuable tor iw precision and love of the exact truta in the courts o! law ard the courts of science, According to these authorities the meteor appeared at Ob. 20m. P. M., in a cloar eky. Some spectators described it ax being as large as ti and ver bright even, in the presence of the sua. followed by « brilliant train, which threw off numerous scintillations, and after ite extiaction iTase cioud of smoke asa residium ot the combustion. Prof. ©. desired to call the attention of the Association to thi extraordinary meteor on two accounts —First, since we are favored with the attendance of men ot science from that part of the country, he hoped they would thoroughly investigate the facta of the cave. and seconcly, he thoaght the singular pheromeua of this body would, if understood, throw light on the theory of these mysterious bodies. Several of the parts apparently ieat to very startling conclusions, The distance of the body, as determined by the sound, woul! seem to be sixty milos rom the spectator; and, if as large as the wu, ite real dia. meter must have been forty miles. But probably the sound did not come from the body itself, but from the fragments hrown off from it by the surface becoming hea.ed, as ragments are thrown off from astone when heated in a urnace. These fragments, in failing through the atmos phere, cause the reports that follow the paseage of the meteor, while tho main body on ite way in its oF. bit. Professor O. bad argued in his paper on the freat meteoric shower of November, Teds. publish ical Map of jes Marcon of Apparent Geo- x. ed immediately after the occurrence, that shooting flare are of a different species from’ these meteors h rain stones on the earth. These meteors t of light, combustible mater, which fs entire burned up at the height of thirty miles above the earth, and are accompanied by neither sound wor falling stones, When, latter chara te therefore, a moteor passes with these stios, we Know it to bean -rolite, and not a shooting star. ‘Moreover, wrolites are not neuatly followed by the reisdual cloud of smoke; but in the case the residual cloud was seep, and suggests the i that — meteor like ymetimos constituted of a solid muck with an envelope and train of nebulous matter, but, in the caso of shooting etars, the body is wholly nebulous, while in the case of wrolites the nucleus only is all that is een: while in other rare cases, as in the Miseissipp! mote both the nucleus and the nedulous accompaniment Present ‘The section then a‘journed. SUPSRCTION OF PHYSICS. Dr, Srenrer in the chat. teresting paper on ordinary i At the meeting of the British Association, j9 1897, 1 Presented a series of experiments in ity which appeared to have a bearing on the efficacy of the licht- ning rod. These experiments afterwaris gave rise to considerable discussion. were brought op before the Lords of the Admiralty of Great Britain, in opposi- tion to the adoption of the system of lightning protection proposed by Mr. now Sir Suow Harris. The commission appointed to examine the plap proposed py Mr. Harcis reported that the facts stated by me ad not militate against it. They were afterwards several times referred to in discussicns which took on the occasion of churebes vetpg struck in London, They were again brought into notice by Dr. O'Staughnessy, of Calcutta, Wav, being called upon ior & plan for protecting powder houres, alter one hid been exploded by a discharge of lightning, advieed that a number of rods be placed on masts at a distance from the building, and gave «5 4 rea- .on for tis peculiar plan the results of the experiments to which | have allgaed. I gave no opinion myself as to the cauee of the phenomena, or of otica! bearing, vptil 1 could bave ap opportunity to farther investigate the subject. Even up to this time I bave never pub- lished ibe continuance of the investigation, though it was mode a number of years ago, I retrained frem publish ing thean, with the bope of being able to give an extended ine oir, embracing Many of my researches on electricity. My appoiwtment, however, to the office | now bold, pre- vented my provecuting there researches, or even pre senting them in depite form aud suitsble detetl to the World, I propose at this time to present a connected out lime ot thew, and to puvlish them more at large, with suitable illustrations, in one of the volumes of the Smuth- sopiep contributions. The facts above alluded to were a OLLOWS = A metailic conductor, intimately connected with the earth at one end, does not sliently conduct the el pwn in sparks On the other end. In one experiy everibed, @ copper wire, one-eighth of an luck 1 dia. meter, Was plunged at its lower eud into the water ot a’ deep well, so a8. to form as perfect fm cop ection with be earth aa possible—a sinali ball vo atiached to the wpper end—and eparks passed on to from a globe of about a foot in diameter. A lateral spirk ould be drawn from apy part of the wire and a pistol of Volta fired even near the rurface of the water, This eifeet was revdered still more striking by attaching @ ball, by means of a thick wire, to the middie of the perpendicular part of a lightning rod, put up according to the dirt ctions piven by Gay Luseac, in behaif of a commission of the French Academy; when sparks of about an inch and a pelf in length were thrown on the ball, corresponding Jnteral sparks could be drawe not only from the parts of the rod between the ground a @ ball, but from the part above, even te the top of the rod. Ip an experiment on atmorpheric electricity, the wire from a kite was supported on an jnsulated reel, and, to prevent accident, an iron crowbar was driven eighteen ipchee tnto the moist earth of a field covered with grass. ‘The wire wag within an inch or an inch and a half of the top of the crowbar, and while vivid sparks were passing through thie space, very pungent sparks could be drawa from the crowbar within an inch or two of the ground. from these experiments it is evident that when elec trieity falis upon the top of a rod explosively, or in the form of a spark, itis not conducted silently to the earth, but terds apparently to give of a small discharge to ail bodies in near proximity. It is well known that a point brought near an electrical machice in full action ds charges the electricity silently by conduction, without proaucing that sudden ruptare of the air called a spark When, however, a rod, with a ball at oae end and point ‘ed at the other, is presented to the conductor of the ma: chine, and the spark received on the ball, a spark wil be given off in this case from the point, and may also be received on another poict. From this experiment we infer that whenever a ro! receives electricity explosively it tends to throw it off explosively. it is a fact familiar to aj] who have made experiment: in electricity that when a discharge from a Lsydea jar is pessed through the ordinary discharging rod wit! a giass handle a feeble spark may be obtained from the rod at the moment of the passage of the eieciri- city. This phenomenon has beea referred, by Biot, to the redundant electricity which always exists 02 the side of the Jar, and is due to the wanto! a perfect neutralization, on account of the thickness of the glass. ‘The truth of this hypothesis was shown by catching tb spark on the knob ot a very small |eyden vial and sub- sequently bringing this near a gold leaf electrometer. In this way it was found that the lateral spark was always of the game kind, namely, plus or minus, as the redundant electricity. By tnereast: the amoust of the later the spe) k was algo incressed in a corresponding degree. ‘This wes readily effected by replacing the smal! knob of the charged jar by a large ball, and an extreme result ‘wes procuced when @ conductor 12 feet ia length wn. ter minated by,balle of about 16 inches diameter, was charg ed and sparks thrown trom it upon an insulated fine cop per wire, @ bundred yards in length, with a ball at eaca end. In this case the wire, which was su; ed hovi- zontally by silk threads, became luminous {rom one end to the cther, with diverging ri on all sides, like the bristles of # cy Lnérical brash, used for cleaniog bottles The phenomena indicated an elastic action, and would seem to require another postulate to our byp thesis ax to ihe electric fluid, pamely, inertia, without weight. When the long wire was doubled upon ttself fo us to make two parailel strands, the rays cisappeared on the inner eiles and were ex iibued with increased length on the other. Thi+ was best exkibted with a shorter wire and illustrated the re puisive action of eketricity in motion, Theee last effects are reacliy referable to the repulaive action of free electricity coupied, az I have stated before, ‘with inertia. When @ discharge passes through a conductor it tends to expand ip the tame manner as it does in a statical con dition; aod from this we may inter that electricity ia a large Conc uctor tends to move near the surface, while galvanic electricity, which possesses very feeble, if any, repulsive energy, prrses through the whole mars. Tue latter fs is inferred from the experimental deduc tun that the conducting power is directly as the transverse section of the wire. From analy ey it bes been supposed that ordinary electricity pervaded the whole mags; and this is probably the case when the diameter of the conductor ‘3 smailin projortion to the quantity of the discharge. fact, however, bas not, #9 tar a8] am informed, beea ehown by experiment that the electricity really pares at the surface when the conductor is of eufficient size. To ascertain whether thi Was the cage, a piece of copper bel! wir middle of its length {nto the form of a helix, and tbis fas- tebed in the axis of a piece of gas pipe, ot about 23 fect Jong, fo that the helix was supported io the middie of the hollow cylinder without touching the sides. In order to make a metallic contact betw«cn the copper wire ip the axis and the internal surface of the «) /eder, a quantity of tia fot! was crowded in aroand the former Toe two ends of the wire were lett projecting eni the helix within was furnished with a large sized sewing needle. full dis varge from a Leyden jar was then seat through the cop. per wire ; the needle was then taken from the belix and examined, but exbibited no trace of magnetim. Ha. the least quantity of electricity followed the copper wire Shich was a much better conductor than the tre), had i: peseed throvg® the epires of the helix and a oy: the needle, it would have megnetized the later The fact that the needle was urmagactived shows that the electricity left the good conductor to pass through the exterior iron cylinder. To render this reselt stilt more evident, the beux and wire were removed from the weide of the ges pipe and were placed on the outside o’ it; each «nd of the wire was Wound several times around he cylinder 5) as to for good metalic contact. Ry this surangemont, when a dicharge was pasted from & Leyden jar th; ough the {roa cylinder, « portion at least of the electricity leit it and passed through the wider etrevit of the wire, and strongly magnetized the needle in the elix. A series of experiments were also made in passing elec tricity through water, and also througn large discs of metal, with some curious results. From ali these experimerts it is evident (hat electricity tends to repel itself and the atoms to separate {rom eacl) other ae widely as possible, whether they are at rest or motion. in There ia another influence, however, which tends, as We shall see bereaiter, to neutralize this expansive force ‘The lateral epark which appears between a priveiple oun cuctor and 2 conducting body {n its immedi ste vicinity, ix but partially ¢ue to the repuisi re energy of the free elec tricity, and is connected with a series of phenomene which deserve epecial attention. When a discharge from Leyden jar the knob removed so as to lessen ae as poesibe the redundant electricity, is sent thro, a long wire, if the length be sufficiently great sparks may be obtained from @ lateral concuctor placed at right argies to the cirection of the principal conductor If the ends of the lateral condvctor, each furnished with a rmali ball, be drooght near tae principa! one, but toe bails at the distance of twenty feet from each other, »' the instant of discharye of a Leyden jar throug the prin. cipal conductor, a briiiant spark will be seen at each ball. If the wire whicb forme the lat erndvctor be dividet into two parte at the middle, and a spiral be introduced the magnetirm of the enclosed needle will indicate a cur rent in the adverse direction to that fromthe jar. if the two balls be brought newrer to each other, tio = gu will be diminished and in some cases re. Agaia, if a powerful ditcharge frem » Leyden jar with the knob removed, be sent through a wire say fifty feet, nnd the knob of a email jar be brought near the wire at the widdle, @ bright epark will a) between the knob of the jar and the wire, Tho the ‘k May appear quite intense and brilliant, yet when the jar is examined jt ie found to con tain scarosty, say, shevwiaty. Ia a aceane silver leaf ful #0 that spark way between the top of ye wire, a brilliant akon be observed, contain My apparently sufficient electricity, if drawn from &@ prime conavetor, to tvar the delicate leaves: of metal in pieces, and yet the remarkable fact is appa rot that the electrometer is unaliected. From these results and series of other phenomena, after Many experiments and a variety ot hypotheses, each of which was disprove? in turn, I arrived a’ the conclas! that at the instant of discharge of a Leyoen jar, the two halves of the wire are in opporite conditions, that a nega. tive wave starts from the end next the outer coating, while @ positive one starts from the other; that they both traverse the whole length of the wire. and neutralize each other for an instant at the miadle, This is in accord ance with the result obtained by Professor Wheatstone, who found that the cietarbance proiuced by the discharge of electricity through a long wire was last percetved at the middle. On hypothesia, the explanation of the brillant ‘K apparently paceing to the delicate clostrometer without affecting it, is readily ox plained, Tet us suppore the electrometer was placed somewhere near & point in the first balf of the wire, then iL \e evident, as the positive wave parsed along, it woult give a positive eark to the electrometer, which would, a moment after, be nevtralved by a epark due to the nv ga- tive wave from the other end of the wire. Io other words, the wire would at first give a spark to the elec- trometer, and before the opening of the ruptare of the air could be closed, cr the inertis of the leaf cowl! be overcome, a retorn spark would be given from the mit ‘pypethecie Fendi Y phenomenon wh ie readily explains » phen’ a bee hed ‘been known, mentiored by the older eieu- triciane, pamely—that ® spark will pass between the projections of a bent wire, for example, if the eS portion of a wire of twenty or thirty feet in tength be bent to the form of a © of oven loop, and the two pro- jecting bende be brought within an inch or two of each gaer briiliant pres Fill spear = the two, his aperiment ae . fe cone PR 4 fact that a to conduction, the el ehorter and more direct pacsage through the air than the longer and more cirenitour one fi the wire. The reult, however, is due to the different condition of the ‘of the wire at the moment of age = One half of the wire being plow and the other minus, ths spark produced is therefore not one of direct discharge, ut one of oscillation, In the passage of an electrical discharge from a prime conductor through a wire intimately coanected with the arth, as to the experiments wenoaes io the pennies of this we may suppose that a positive wave passes thom due end ‘of the wire to the other, and that ibis is preceded by a negative wave, the result of the induction or repulsive er ergy of the free electricity which drives, as it were, before it, according to the theory of a single fluid, the natural electricity ot tbe con ductor, It is this negative wave, or unsaturated portion of matter, which precedes the positive wave, whioh me” , tralizes it and tends to prevent the natural repulsio” , o¢ the particles from dissipating them into surro’ aging space, The negative wave, however, is mush fess in tense than the positive, and, therefore, umes the kaod of the smal! jar on which thewpark 1 receive be brougt t very near the conductor. the uegative wage will not be euflicient to rupture he intervoing stratam of air, ana hence, in thie case, but ® very parttal neutralization will take place. There 1s, LoWever, another action, as we sball see hereaiter, Whic'a tends to diminish the final quantity of the lateral O.scharge. a series of experim~nts were afterwards made upon electro-dj nam ipduetion, in which an tnduced current wes produced ina conductor placed parallel to the pri mary. ‘A tull account of these experiments, amountivg as they did to several bundred, indeed 1 may say thousands, would occupy more time than that allotted to me on this occasion, 1 will, Lowever, inention that the direction of the induced current was obtained by the magnetization of sewing needies in the axis of maguetizing spirats, and aleo m some cases by the position of the hole ia a plerees d.. With the same strengeb of charge and the same length of cordectore, a charge was produced in the may netik#m of the .needic by the mere change of distance by the proximity of a third conductor, b, a break so as to produce a second spark in the circvit of the first conductor, by @ brenk im the receiving conductor; again, when ali the conditions were apparent ly the same, a shange iu the eize of the needle, and inthe simplicity and complexity of the spiral, would’ produce « ciflerence in the directicn of the magnetism. At first these results would lead to the conclusion thar the magnetization of the needle could not be relied upow a8 an indication of the direction of the disebarge, and yet the result ia the case of a galvanic current is always so deQnite, that, admittng the identity, or evon the genere! anslogy ot the electrical aud galvanic principles, the idea could Lot readily be abandoned that these variations |u the magnetism were not caused by some peculiarities o1 action in the current itself. From these results, and all those I have previously de seribed, L was led, afver disproving a variety of other hy- potheses provisionally adopted, to the conclusion that all elecirical discharges were of an oscillatory character. ‘The adoption of this hy oethente enabled me to explain all the phenomena, and led me to collect under one point of view various groups of results which before seeme:! to be in accordance with no law, or Wereapparently inex plicable, 3 It we adopt the hypothesis of one fluid, which has be abundantly chown leads to the same result in the way mathematical deduction as that of two, we may supp electricity to consist of a fluid, the quantity of which is slightly increased on the inner side of a coated jar, whi! it i2 slightly diminished on the outer coating. ‘In the act of the discharge, the redundant electricity of the inside is rapidly ‘precipitated through the conductor on to the outside; from this it again rebounds sending, as it were, a wave in the opposite direction to the instde, and again a third ia the first di rection, a fourth in the opposite, and so on, each succes sive wave becoming lees intense until the whole dyra mic effect is expended in the resistance of the conductor. ‘A clear conception of this mode of action enables us to Indicate, @peon, the direction ef magnetism which wi!! result ina given needle when the circumstances ar: known, and also enables us to s0 modify the condit ons that a desired Girection of magnetism, in any case, may be uced. ¢ also enabled to indicate the action of each oscil lation separately, and to prove at least the existence of four or five, the last of which may give the direction to the magnetism of the needle. To understand this. let us suppose that in the discharge of a Leyden jar there are four waves, of which the first is greatest in amount and each jess in succession. To give precision to our ideas, let us suppose that with iver sized jar and @ given intensity of discharge, the first wave to have a magnetizing power ot +100, the second of —50, the third of 4-20, end the fourth of —5; and let us further suppose that the needle which we place in the spiral, wh.ch in this cage is composed of a eeries of siny!e spires, bas a magnetic capacity of 10 units. Now, it is evident that if there were but one wave, and thatthe Uret, the needle weuld be Lap yey with the full power of that wave—namely, by the force indicated by 100; but if the discharge cone ists of two waves, viz:—one of +100, an the other of —80, then the second wave will neutralize « portion of the first, ani the resultant magnetism of the needle will be indicated by +50. ‘The third wave would tend to add a small amount to this, and the fourth to diminish it. But it is probable that the reflex waves will soon become too feeble in inter sity to overcome the coercive’or retentive power of the hardened steel. If, however, in this case we consider all the waves ective, the resultant magnetism will be 62. or the difference between the sum of the plus and minus waver. now increase the amount of the charge uptil it becomer three times as great, and if we suppore the Waves to increase iu the same proportion. the mag Letizing capacity of the needle remaining at 100, then th “magnetizing power of ibe four waves will be represente: by — 100-1564 00—15, ‘The Bret wave will magnetize the needle to saturation viz.: 10@; the #ecend will neutralize the effect of thi. Wave and impart —50; the third wave will noutrahz: this and jeaye +10; the fcurth wave will again neutral ize this 10, and leave —5, as the final condition ef the peedle, or in other wore the resulting megnctism will be—5. If now we again increase the power of the charge until jt amounts w seven fold, the gr etizing power of the several waves will be repre e 10110WS: 4-700 —350 +140 —o5. e the Srst three waves will produce amgnet jem of 440, which the last wave will reduce to +5 ing +5 us the resulting msguetism. By increasing the amount of the charge, end thus exaltiag the magnetizing power of each successive wave, the fourth wave will be come the ceminant one and the resulting mayvetism, will be again rninug. ‘The same result may be produced by rendering th- fpirals mcre complex: thus, by mereasing the namtcr spires until the econd wave exceeds the magnet'z: the needle, we shall then bave a change ‘ gretism; avd if the pumber of spirce is still further in ercased, the third wave may be £0 exalted as to impress the needle with the magnetiem due to its direction. In this way each succeeding wave be made the nt one, and each chenge in the direction of the Magnetism ot the needle, the number of spires being tly increated, while the charge remains of the ¢ intercity, wilt indicate an addmonal wave. The e incicatichs will be obtained if we gradually increase the intensity ©: charge, the spirals remainug the same. A renes of charges can alao be exhibited by using nee. dles of Je: d lees Crmensions, or in other words, o° mailer and smaller magnetic capacity, To exbibit w cilect of the several waver bya discharge it is only pecestary to jotroduer wit a Dumber of magnetizing spirals, ench successive one of which is compored of @ loss number of pirea—each of these being furpisbed with a needle of the When the di ‘ge is made, it the spires are ‘r number, we sbail have a reries of alterni the direction of the mag netiem of the needle, or if we introduce into ibe same circut a number of spirals. each of the ame number of spires, and iurpish e: with ves gradually diminishing, we shall bave in this care also a series of alterna sone. These inferences were fully verified by repeated experiments. By away: J in the line of a conductor, transmitting « rge of free electricity from a machine, a geries of ginduated mag netizing spirals, each charged with ancedlo of the seme size, several oxcillations were detected; the ‘ery this case, however, to be much lees imense than the primary. It will hence ap pear that whenever the electrical equil’brium is restored Alter it bas been disturbed by the action of some me chanical or chemical force, it \enés to return to etate of normal equilibrium of uniform diffusion by « series of oscillations. This would indicate inertia, and an actual transfer of a substance from one portion of space to snother. In the explanation of the phenomena of electricity, and of light and beat, the ption which we can entertain is that of an etherial medium of matter, the atoms of tate of great tenuity and self repellant. So lore as this ie cavally diffused throughout space ans je at rest no electrical phenomena are exhibited; put en it is accumulated in one portion of space and di miniehed in another, electrical attraction and repulsion are the consequences, and im the discbarge of ele*trict*y there if an actual tranefer of this etherial matier from one part CO sag 2 to another, and the equilibrium is then rest by «series oscillations pre cisely analogous to the cessation of motion in air or any other elastic fuld, Besides this transfer o the eiherial medium through space, we may conceive ot a disturdence on all sides of a conductor propagated wave 4 this may give rise to the dynamic indu sty produced by frictional electricity, of which I have belore * en. ‘The electro.dynamic induction in a parallel wire by « electricity ha long conduc tor takes p rprising distance. A single spark ‘of electricity rent through a wire may be proved to distord the electric equilibrium of a space of several cubic miles in capacity. In one experiment needies were ‘Magnetized at the distance of three hundred yards irom the wire A aaa which the Ciscbarge of asingle «park was : pasted. Dynamic indvct on 1s aio produced ata remarkable dis tance between two metallic dices 0 circles were made of wood and covered with tin fou, each of about feet in diameter, when one of shese was suspended m the pri conductor of a machine, and the other placed nineteen feet below, with two wooden floors & two plaster ceiling? between th a0 inductive spar wan perceived between the kanckle of the lower ove at the moment a rrark was drawn from the upper one. ‘We may infer from this experiment what effect an eles trical diecherge in the heaveus must produce in distarbioe the electricity of the air and the suriace of the ear The electricity of hundreds of square miles of surface im ably, at least, slightly disturbed by every intense eh of lighte'ng whieh takes pace betwee clout acd cloud, or between the cloud an the earth T have ftated in previous publications that the prinetpal disturbance of the electric telegraph is due to this induc tive action at a distance. To study the inductive effect of a discharge of lightning Ata distaice, a copper wire was soldered to the metallis roof of the house i inhabited in Prine The wire pass. ed down the wail of the houre on the onte| study through a bo d down ie the casing of the window and then ‘out sgain onder the lower and terminated below the curface of the water ie a deep well near by. To in- crease the contact with the water, aniron spike was at: tached to the end of the wire. The middie of the por- tion of the wire within the houre was cot in two and a megnetizivg spiral inserted ip the opening. After thie en been competed 1 waited with consi derable impatience for the oocvrrence of a thunder storm, end the firet took ear'y in the thongh the thoncer was distant, I fownd i the needle strongly magnetized, as if by current. A reries of ere! eplrale wi wards jntrodnced into the opening of wire, and during the ocenrrence of an inten: explosion three alterations of the direction of mrenrtiem were eb: served, proving conclusively that the dirtarbance pro. . inductive action of an electrical di sives TiC" 4 series of oscillations ret GOP" cading this general account of an extonded se Tien or 2Xperiments, which occupied a consilerabio po {eRO". sil my leisure for wmumber of years, it may be aght fit that 1 should give my opinion of the practicel aring of the results upon protection affordet by the vabtning rod. From what! have stated it may be rea: inferre} that during the passage of an explosive electrical discharge through a& mewlie 10d any given powt if on its surface is charged for an insiapt with & succession of plus and minus waves, and that cvs quently it tends to give off a spark, the intensity of “a will be in proportion to the suddenness and intensivy o! the explosion with which the discharge falls upon rod. That lightuing rods are struck explosively is pro by the fact that the points are frequently melted, thou: it appears Ubat the intensity of the discharge is much re duced when received upon a point. Ihave been in a building on two occasions when the lightning descended the rod, and in both coses the timy of the e was prolonged and attended with a biss ing courd. 1 think it probable that a large namber of pointed lightning rods in a city tends considerably to mollily the severity of the discharge, Thad lately an opportunity of observing the effect of the lightning on the rod of ‘the principal tower of the Smithtonian building. During one of the most severe vtorms we have had this summer, and while there wa asbort cersation in the deluge of rain which fell, Tas- cended to the top of the tower, above which the lightning rod extended about ten feat. The exhibition was grant in the extreme. The lightning appeared to be playing iv every direction, almoet within reach; the top of the roi was constantly tipped with a bright star, and at every ach it gave cil a bissing nots Prof. Hare made some remarks on his theory with re eard to electricity. Vrof. MeCcirccn moved that a time be appointed for Vroiessor Hare to be heard on the subject. Carried. ‘The following papers were then read in their order :— On the atomic weight of lithium, by J. W. Maier, of Alabama. ‘on the forme of the atoms of the simple substances chemistry, a8 indicated by their atom ¢ weights, by Sr ication of Nuremberg’s apparatus by ‘about four or five miputes, by SANDERSON SMITH, On cfllorescence from brick masonry, by E. B. Hust, ‘The next paper in order waz SOME EXYERIMENTS ON ‘VISUAL DIRECTION—8Y PROFESSON JOHN BROCKLESBY, TRINITY COL}EGR, MARTORD, Some years ago, I met with @ brief allusion to the oxist ence of an ‘ bssay on Sirgle Vision,’ published by Dr. Woodhouse, in the Philosophical Magazine.’’ In this lweatise, it eeems, the author endeavors to prove, fi certain experiments end phyvioloxical consideration: t one eye is wholly occupied with vision, while the other is nearly or entirely passive, My attention was arrested by this iaference, and, as the essay, with its detailed ex- periments, wes not accessible, | was led to make somo ipvestigatiobs upon this point and at others kindred to it, ‘These investigations and the conclusions to which they lead are the subject of the present paper. It is well kvown tbat if, while looking at aremote object with both eyes open, we interpose a secon’ at a short distance from ug, the latter will appear double; the image formed by the right eye being seen towards the left hand, and that formed by the left towards the right hand; the proximiiy of the images depending upon the magnitude of the inter- posed body and its distance from the eyes. As we can- not, at the same time, range both the separate images of the'nearest object with the remote one—and yet as a mat- ter of fact we do in some way rap; bj thus situated, when beth <= are oper—it follows that a solution of this point touches on the one in question. In order to ascertain in what manner I was enabled to range objects at diflerent distances by double vision I insticuted the following personal experiments. How far the results ‘obtained are to be regarded as general will appear in the eubsequent pages:— Range of a Point nar the with an Object more or tess Kemote.—If with both Fey B a I bring be- fe me, beyond the limit of distinct vision, a small point that of @ pencil, and endeavor to range it with some object more or lees remote, as ibe on a wail or the ball of a spire, I find that two images of the point at once yut that the seen by the right eye is imme- nd involun' selected as that w ranges with the remote object. This is proved by the fact that if the left eye is cloged the -— is still preserved; but if the rigbt eye is closec and the left remains open, the range is destroyed, the point being secn to the right of the distant object’ Moreover, if, reversing the experi- ment, I firet bring the point and object in # line with the right eye alene the left being closed, it is found that they continue in a Lay + when both eyes are open; but that if the range is first taken with the left ‘eye only, and the objects are then viewed with both eyes, the rapge ccases to exist, the ea being seen to the left of the object ese charges in visval direction are more marked when the point is brought within the hmit of distinct vision and the eecund object is a few feet distant. Upon taking two or more points, instead of one, and ranging them with some object at a distance, the same results occur as in the former case. The optical effect, however, is more striking than when one pointis used, and the power of the right ey« to control the range is Very cvident. Sinze an jatiaite number oi material points, placed one bebind the other #0. as to touch, may be regarded as forming a straight line, it might be reasonably inferred that a straight line would ‘bt the same phenomena in respect to visual direction umber of polnts. Experiment shows correct, for up» ranging a line, as the edge of a rule, with a second object, both eyes b sing open, ‘be range, upon cloring the lett eye is still maintained, but is lost when the right eye alone is closed, the edg» in the last care not being seen in the direction of its ieagth but obliquely. If also, as before, the range is first taken with the rigbt eye, it is preserved when both eyes are open; but if with the left, it is apparently lost whoa viewed with both eyes, Konge of a Surface —If similar experiments to those ust detailed are made with a surface of smal! extent, the ome prevailing power of the right eye to coutrol the vi direction is stil! manifested, but is most strikingly ex hib-ted when several surfaces are mace to range with a fixed object. Thus, if a number of bright objects are taken, as the flames of several candles, the ruling power of the right eye is finely 1eveaicd by ‘liret ranging the flames in a line with both eyes, and then beholding them with each eye alone. Range of a Solid —By the union of numerous materia! surfaces, cqual each to esch, and baving their centres ia the aight line, solid cylirders and prisms may be formed i the same law of visual direction that be. lovgs to these surfaces belongs alvo to the solids that they compore; for if s smali straight rod is sighted to the direction of its length with a tecond object, in the Various ways tat bave been mentioned, the range is the same when it is viewed in succession by the right eye and by both eyes, but diflerent when the left is used in stead of the right. Range of an Opening.—It a ring ie taken, or a card with an opening in it, and the card is so held that 1 look through the opening at some distant object, both eyes being open, ot the opening formed by the nly perceived; but it is only through that which wv the right eye that the is seen, for i! the left is closed the object is still visible through the opening: bat if the right is closed and the ‘eft is open, it tr'no longer seen through the orifice, If the range at Gret is taken with the right eye there ia no sbiifting of the visible direction of the object when both eyes are employed in yiclon—the left coming to the aid of-the right; but when the range at the outset is taken with the left eye, and the right ts then opened, the influence of the left eye upon the ange ‘s pee Tare apd seems almost destroyed by the power of the right. If, inete.d of one perforated card two or three are «employed at tame time, the object being viewed throvgh the cards placed one bebind the other, the influence of the right eye is rendered more oyident; for when the object is first seen through the eevera’ open. ings With both eyes open, upom closing the right, not only dees the object become hoor bot — ‘the open ings also. instance, 1 may see through the openin, of the fret card the unbroken face of the recond-—the ork fice in the latter being out of sight. @ Nibe—A tube be ded as con- mber of material . It might, there- to tthe same vieual phenomena vpon Iroking throu; ferent ways tbat 4 ’ al attention to the left eye it may be made to cont the range instead of the rigat, and objects can be seen by it in the same Cirection as when viewed by both eyes; but this contro] ceases with the particular effort will that calle the eye to discharge an unusual daty. normal condition of vision, rig points, faces and solids, near to the observer, i¢ always deter. mined by the right eyo. But a question arises, is this dominant power of tiie e & peculiarity cf the individual, like Daltonism, or is generally truer In reply, [ would state that | bave been accustomed, for a length of time, to propose some of the preceding experiments to different individa- ale, and the results bave aimost invariably shown that the right determines the visual air eighty cases, pot more than three or four exceptions fron this rule bave been defected. In one of these exceptions the it eye was weaker than the left, and the latter dis- chsrged the functions of the former in the aforesaid ox peritnente, and vice verea. Another exception occurs in the care of a civil engineer, who is accustomed to right objects With both eyes open, by glancing snddenly from one to the other. in this instance, the observer when ging near object with a distant one, with botn open, inds the tmage of the former to be situated cof between its two positions, as With each eye se. rately. Tn View of thege facts, I am inclined to believe that moat pereone, when they gave upon a near o¥ject with both eyes open, babitually neglect the image formed by the left eye, and employ that of the right to fix the visual dircetion in fact, that we are right eyed Moreover, that caser ecmetimer occur where the lett eye is used for this purpore, and in euch exceptional instances the observers may be termed left eyed. A boy shoots marbles with both eyer cper, ard a sports man not unfreqnently brings down hit peme in the fame manner: but | apprehend that in oth instances the aim is ae truly taken as if one oye wet t the range. If it * tree that the right eye, under the circumstances ned, poreerser & superiority over the other, the thet would be in strict recordahce with some other phyriolog: cal phenemena, Weare ail aware of the pre eminence which the rigbt hand bas over the left, either from habit How much more ready and quick it is in being the fret to advance whenever the £0 marked is thi¥ characteristic that we term experiners ond activity of manipulation, dexterity, Right bancedners constitutes the law, left handedness tie exception. The same fact is observed in respect to the feet. In the game of football, for instance, the right foot naturally comes firet into play, and im decidedly more active than the ober, The superiority of one organ of vision over the other would pot therefore constitate an ancmoaly, neither would it be curprising if the eame phe- nemenon ehowld be fourd to exist im respect to one or mere of the other verses. While making cme ofthe preceding experiments, tt coourred to me thet there a possibly exist such a sympathy be ween the eye and the hands that the right Deno acts in unison with the right eye, and the left hand with the left eye, eo thata left banded person would be ail ite metic hand is neeced. found left eved, asd a right handed, right eyed, In ord to solve this point | had recourse to'one who was a skil blacksmith, and who used his left hand exslusivoly wielding ibe bainmer; but Mf this case it alao ' a8 in those of ricit handed persons, that the right ¢ took precedence of the left, and the Supposed unison action did not exist’ Thus’ far the visual direetion o near with a distant object has only been considered: | this point ray be examined still further, both in ref ence to two remote objects and to the extent of rar when we look through an opening, Ifa surface of'e siderable extent, a8 a board a footl wite or more, placed at # moderat- distance from the observer, for stance sixty or seventy feet, and this surface is m upon the wallofa building at some distance Debind tnd that the space on the building which the board o ceols ig not, as in the case Of a near object limited by | right eye, but is determined as follows:—A line dra from the rignt eye to the rigbt hand e4ge of the board a continved to the wall, fixes, in the normal state of visi the right hand limit of the concealed portion of the wi and a line drawn from the left eye to the | band edgeof the board, and the to wi determipes also the left hand limit of the hidden surfa for, having firet projected the board upoa the w with both eyes, 1 Sno that upon ae the right oye viewing the board with the lelJ, the right hand edge to the right, while the left edge is unchanged In sition; and that when tue right eye ts open and the Closed, the left band edge shifts to the left, but the of cdge’keeps its first place. When, therefore, both o are open, the right controls the visual direction of | right edge of the boa’ nd the left the left » T fact is eull further proved by first viewing the o| w each eye and then with both. The horizontal visual Ea, Serene. under which the surface 1s seen, wl both eyes ars open, is Jess than that under whioh it is held with one eye, by the amount of the avglo formed drawing lines from each eye to one of the vertical edg A different rule appears to obtain, in respect to. the hc zontal extent of view that occura, when we gaze thron @ large opening, as a win low, upon the landscape bef: us, By experimenting in the way already mentione: tind the limiter vision to be thus determined : a | drawn from the right eye to the left hand side of the v dow, and produced onward, gives the position of the | band boundary of the landscape, and another line dra trom the leit eye to the right hand side of the wind determines the rigbt hand boundary of vision. By ec paring these results with those immediately preceding appears that when a landscape is observed either thro: ab opening, or partially obscured ay. some iaterven object, both eyes are employed in Oxing the limits of sion, but in a diferent way, yet in such @ manner tha greater extent is seen with two eyes than wih one; in first case by increasing the visual angle of the la scape, urd in the second by reduciog the visible an of the obscuring object to a minimum. ‘Then followeo a paper ON THE WATERS OF ST. LAWRENCE AND OTPAVA RIVERS. ‘TH, STERRY BUNT, OF THE GEOLOGICAL SURV#Y OF CANAL ¢ river St. Lawrence consists of a series of gr separated by shut channels, and the jae is that the water, purified by subsidence in these is, anlike most other great rivers, at all times teanspar free from suspeaded matter. Tho true of waters of the Ottawa; but this latter ris flowing for the most part through forests and draix vast marshes, holds in solution a prepces of ganic matter, eiving it an amber tit, which contr strongly with the clear bluish green color of the St. Li rence. The waters of the latter are principally deri opts palmcaize rein, while those of the Ottawa f lor the most part from an area covered crystal ayoic rocks. a ‘The waters of these two rivers were taken for jvat above their juncgure, and towards the end of before the melting of the snowe. The St. lawrence ¢ tain, in 10,000 parts, 1.678 of which 1.538 parts are fixed at a red heat, ecnetets of carbonate of lime and ee ee chloride and eulphatcs, and carbonates of ies, 80 portions of alumina, iron, manganese send uae Baer ps 1560 wa water is 0.697 sohd matter, of which 0.534 pls? The in Gients are the same as those of the St. geo but proportion of carbonates of lime is smaller, and a much greater, equal to 0.26 parts. sulphuric acid, pearly sufficient in the Lawrence to saturate the alkalies, aro found in a sma proportion im the Ottawa water, where the alkalies appear to exist combined with ap acid, and are converted into carbonates by ignition, © of potash to the soda im the case is large, a8 might be expected from the aecompor: felspatbic rocks which have provided the soluble ters of the Ottawa water, in which we mies the amount of soda salts of chlorine and salpburic acid characterize the St. Lawrence. The large a: silica which—which is prebably always potable waters—bas hitherto beem overieoked by! chemiets except <ainte Claire Deville, but ie of great} portance in a chemical point of view, indicating during the slow decomporition of mineral silicaes the influence of carbonic and organic acids the sili set free in ascluble torm, which may afterwards pi important part in the silicification of rocks and the sediments of lakes and seas, and helps greatly to Eee fertilizing action of irrigation upon cultiv: mn The section then adjourned. SUB-SECTION OF METEOROLOGY. ‘The first paper read here was ON THE TYPHOON OF OCT. 28, 1854, AT THE noNTW Ist. WITH A SKETCH OF ITS BAROMETRIC CURVE, AND 3 OF OTHER CYCLONKS; BY JOUN RODOERS; UNITRD NAVY, COMMANDING UNITED BTATEY SUMVBYING & TION." COMMUNICATED EY W. C. REDFIELD Commander Kodgers states that out of bis own ence he is @ believer in Mr. field’s of cones, and that this theory had enabled him to ay storms into wkisn be would not have been have been involved. On September was in North’ ipogtiuee in latitade 24 minutes North, ude 119 degrees 17 minutes The weather was regen the ship standing to southward, with across violent sea, and ‘Wind, increasing in frequency and force. He says:— T considered that I saw a cyclone before us,and avoid its force by sailing away from it. We then stood northward. The barometer soon rose, and the wind rated. At the Bonin Islands, Get 28, 1834, we had a The harbor of Port Lioyd Is formed by the crater of an voleano. The sides rise precipitously above the water height of some twelve bu feet. | You will percei that the anchorage must be in & good degree protected the violence of the wind, yet it View awfully. “Te leaves from the trees, all gestion, wae even the sweet potato vines in the sheltered destroyed by it, The evening before the hurricane the surf beat beavity upon the mouth of the harbor than | hadever it, Had we been at sea, 1 bave little doabt bat should Lave known of its ‘ach. This storm is 3 nied by an accurate detineation of the fall aad rise ‘ba: ometer in thie cyclone, as shown by more than euecestive and careful observations. foll {rom 29.90 to 28.45, The duration of the orciliation was thirty #ix hours; that of the gale a hours. The wind in this cyclone veered N.E, by E., through & to W. 8. W.; being 8. 4. B. the barometer was at {is lowest point, wbich was 2. ‘As no lull or remission occurred at that |, on the date above tent! 20°F It commenced at E.N.E. put bia ehip on contre path of the cyclone, he would then no damage. Many severe lee: of this practical have been given 4 saviguen. ' Then followed anotner paper by Mr. Renretn om WHTRLWIND AND TORNADO VORTICES, Aspiral rotation constitutes the essential these remarkable movenents in the atmosphere. gards the interior anc the more exterior portions whirlitg body, the course of the apiral —, to the right or the left, 1s one and the same, hique inclination which the spiral movemect also i the plane of the borizun, in these two porvons of the] tex, is found to be in opposite directions. Thus, cutward portion of the whirlwind the tendency is werd, when the axis is vertical; but in its 1 erlor the spiral inclination aud tendency are upward. explains the ascension caminutiye whirlwind: the air at the earth's surface, gradually descending movement in avymetric whiel ie that cf a closing apiral, while the course of the 1g movement; ip the interlor portien of the body, «tan opeving spiral. In the aerial vortex of the ascending movement or ar the emaliest porjon of the bedy, on that its rotation is rtionately more pot stense, peing produced mentum of the surrounding body, converging creasingly rapit motion into a emallor arca. vortices, the epiral inciin ia reversed, the © horinal course “ ccnding spiral bein, tie exis of the vortex. Heneo, lighter bodice, aut bubbles of air, fien forced downward jn the in the monner in which heavier bouies ara ward in the verial vortex. The spirality and jnell in the great portion of the whirling body which ie rior to its axial region, is not ordinarily subject to observa'ion. ‘The foregoing i# simply a statement sults which I have derived from a long course of vation and inquiry. THR YELLOW PRvVER, ‘The next paper was ON THE METEOROTOGICAL PTENOMENA DURING THR ‘The Lange permission of pene the reeriving ship at the Norfolk 5 ly, August, September and Cetober, monthe of hart was pr by Professor to Po veeucs, represe| On these dat ster, which was exhibited