AUCKLAND INSTITUTE.

New Zealand Herald, Volume XVIII, Issue 6107, 14 June 1881, Page 6

AUCKLAND INSTITUTE.

The session of the Institute for ISSI was opened last night, in the Museum and Institute Building. Tbe Secretary (Mr. T. F. Cheeseman) road the list of new members elected sinoe last meeting, also the list of donations, as follows : New Mesibers.— C. Alexander, J 31. Alexander, A. Buckland, 11. Campbell, M. A. Clark, W. C. Coloman, P. Comisky, ,T. Fisher, T. T. Gamble, D. Goldic, G. Johnstone, G. Ilemus. T. W. Hickson, T. Mahoney, Captain McGregor, T. Maekay, D. Nathan, E. 13. Parsons, A. Saundcrs, G. Sibbin, J. C. Sharland, 11. H. Stevenson, E. 11. WhiUker, \V. K. Waddel, Auckland ; Major T. Benton, Northcote ; N. Kenny, G. T. Wilkinson, Thames; T. l>. Moodv, Kawakawa ; d. M. Sheppard, Otalmhu.

Donations—Journal of the Geographical Society for 1870, J. T. MacKclvie; Reports of the Smithsonian Institution for 1877 and IS7S. several pamphlets, tho Smitlisonian Institution ; Proceedings "of tho Linuean Society of New South Wales vol. 5, part 2, the Society; Murchison's Russia and Ural Mountains, Colonel Haultain ; old map of Auckland. A. Brock ; six vols. of books on navnl architecture, &c. J. WayAickin ; IGS bird skins, 26 reptiles, 10 miscellaneous specimens, received in exchange from Dr. Garnier, Canada; New Zealand bird skin 3, E. A. Plumley ; New Zealand bird skins, F. H. Combes ; skin of dabchick, T. Munro ; two North Island kiwis, Major Mair; fallow deer, fnom Motutapu, Messrs. Reid Brothers ; giant petrel, J. Kcmlcrdino; specimens of helix busbyi, W. J. Palmer: living specimens of helix busbyi, J. ltocho ; New Zealand shells, specimen of hammer-headed shark, G. Johnstcue; lizards, beetles, &c, in spirits, 3lr. Shepherd, I'uakau; fino specimen of globe ftah, Mrs. J. M. Shera;.New Zealand shells, C. Matthews; foreign shells, J. Dcnn'son; moa. bonoi, — Williams; unusually line gold specimen from the Success mine, Coromandel, the directors of Success Gold-mining Co.; fossils from the tertiaries of Itiiwke's Buy, S. Harding; arnbrit from Kanukitiva, I3.ay of Islands Coal Co,; landscape miirblo, celeStino, and other minerals, F. 11. Paul; large rock crystal from Australia ' (locally known 'as the Butter's diamond). Mr. Reynolds ; fossils from the Day of Islands, J. •. Pond; Fortuua Islamd, Captain Carmichaol; samples of Lincoln long wool, Captain Daldy.

The President for the year read: his inaugural address, as follows :— In accordance with tlie usual custom, it now becomes my duty to deliver the inaugural adaress. In the Erst place, I desire'to express ray appreciation of the honour which the members of tho Instigate- have conferred : tipon me in electing me to fill the President's chair—an honour to which my own feelings would not have prompted me to aspire. Standing on the threshold oE our fourteenth session, and looking back to the meeting in November, ISG7, at which, with zeiious intention*, not unmirigled with misgiving as to its permanence, our society was launched, I feel that there is true cause for congratulation at the progress niade and the success achieved. And looking forward, there is every rousois for encouragement. With a membership numbering 305—the largest roll of any of the affiliated societies—including 23 mimes just added, we have the evidence of a sustained interest in our important operations. Having been associated with tho Institute" as a member of council at its beginning, I know that much of the success has been owing to the fostering cire and over willing assistance rendered ; br Professors Kirk aud Hutton in the early years of our existence.

Our aims embrace the cultivation of science, art, literature, and philosophy, a range of subjects whici- gives ample scope for the indulgence of every taste, while our meetings afford a congenial sphere whore e«h votary ciin minister to the pleasure and edification of his fellsivs, receiving in return an impulse to fresh exertion, whether it bo to study, to assimiUte, and profit by, the wealth of thought, feeling, and -wisdom treasured up in our national literature. Or in the field of Nature, animate and inanimate, to observe and classify hur phenomena, and evolve the laws that regulate hoc processes, '- With curious eye To glance at beauteous things that give delight: Objects of earth or air, or sea or sky, That bring the very senses in the s gut To relish what they nee." SCIENCE. But granting that art, literature, and philosophy are wisely included in the aims of the Institute, and well deserving of attention and encouragement, science must naturally occupy a prominent placo in our deliberations. Daring the present century alono it has received a development so enormous in its extent and so fruitful in its influences on our civilisation as to be unparalleled iu tha history of mankind. So multitudinous are the facts observed, so numerous the generalisations formed, and so fertile the deductions madu therefrom in suggesting fresh inquiries,that the subdivisions have become special studies. Division of .labour has become essential to further progress. Never before have the sayings aud doings of scientific men had so large an auditory, or received more enlightened attention. It is true that the bold theories and far-reaiihiug generalisations which have been put forth in some departments have caused uneasiness and oppositien on the part of many. Especially id this the case in biology, in the well known THEORY Of. EVOLUTION.

I will only say in passing that it is vain to object to the indulgence in theo'y. No one can intelligently observe natural phenomena without theorizing or endeavouring to conceive the mode in which they h;ive been brought about. Following after the preliminary collection of facts, theory offers a connecting link, a centre of aggregation, round which other facts may be orderly grouped, or their divergence be clearly perceived. Let hypothesis be freely submitted to the scorching heat and glare of criticism, to the crucial test of comparison with the manifold facts and observations of keen and competent men, bearing directly or indirectly thereon, and truth, which should be ever welcome, will bo the resultant. Should the hypothesis fail to account for, or he in accord with all the facts, then must it be discarded for a bettor. That which is true will stand, while that which is false will be done away. But even if a theory which at first appeared plausible has to be modified or sot aside, it may have subserved a useful purpose in stimulating and guiding inquiry, concentrating attention, and methodising observation.

To revert to the theory to which I have just alluded, it must be admitted by candid minds that tho intense activity displayed in the field of biology is limited at two important points. On tho one hand there is the gap between the inorganic and organic forms of matter, the production of that protoplasm which is the basis of all living bodios, with its wonderful potential qualities. The general testimony of science is that the innumerable forms of existing life spring only from antecedent life : that theroia no such thing as spontaneous generation from dead matter; that no chemical attractions or affinities can avail us here, and so if we go back in imagination to one primordial cell or germ as the beginning of life we must still look to a pre-existing life or active agent for its production. On the other hand, there is the impassable chasm which exists between organic matter aod She profoundly mysterious thinking part of man. Their close relationship and interdependence may indeed bo studied, but tho nature of the mind itself, so distinct from matter in its independence of extension iu space so widely apart from the objective phenomena of the external world, and so evidently antecedent to the sensations which they produce withiu it. This, notwithstanding elaborate groupings of words in explanation, is likely to remain an insoluble mystery, and defy conception to the present powers of man. GROPPB OF SCIENTIFIC SUBJECTS. From a colonial point of view, there are two groups of scientific subjects that may engross our attention, which, apart from the relative interest derivable from their pursuit, present differences in the facilities for their study, and the original or intrinsic value of their results. la tho first, wo may plaee botany, zoology, geology, mineralogy, meteorology, and ethnology. In a new country there is abundance of scope for useful and accurate observations on its flora and fauna, its geological formations, its meteorological phenomena, and the ethnological peculiarities and history of the native race. These are within tho reach of all, and offer opportunities for giving some original contribution to tho stock of human knowledge, facts of observation which may supply somo missing link, or throw .1 gleam of light-athwart some obscure point, or which, from their local and distinctive character, will be as stones which the great European master builders in each department will gladly aceeptae necessary components in the great and noble edifice of science. The other group may bo said to include applied mathematics, the general science of biology, the physical sciences, astronomy, hoat, light, electricity, magnetism,

! chemistry, mechanics, hydrostatics, and pneumatics. In those branches in which the investigations are either general in their character or demand for original .research appliances and leisure not readily available in the colonies, we must be content to keep abreast of the knowledge attained and the discoveries made. But, to do this is an important function of this Institute, and it is worthy of consideration, whether, without disparaging the good work which has been done and still requires doing, in preparing and accommodating our zoological specimens in the Museum, it might not be desirable to acquire, by gradual steps, an equipment of physical apparatus which would be suitable for the purpose of exposition, and possibly for original research on the part of some of the mombers. Meantime, the magazines procured for the use of the members, the library of reference, and occasional lectures have rendered good service. ■\Yith regard to the first group of subjects, the New Zealand Institute has done good work in every department of nitural history, and no inconsiderable part has been done by the Auckland Institute, while, thanks to the liberality of members and citizen?, led bythe spirited example of ono of our leading members (I allude to Mr. Justice Gillies), our valuable specimens have received worthy shelter in this excellent building. By the system of exchanges, too, we have been enabled to confer a favour upon European and American museums, receiving in return representative specimens from various countries. MATTER AND FORCE. There are two subjects which embrace the whole range of the physicist's attention. These are the various subjtanceii which are to be found in external nature, and the forces in operation which produce the everchanging phases of matter. As bearing upon soma of the results of the year, to which I shall afterwards refer, I desire briefly to direct your attention, and refresh your I memory on the present position of science, with regard to matter and force. The undoubted tendency of scientific philosophy is to establish a unity and simplicity out of apparent diversity and complexity. To reduce in conception the 64 elements of matter to one ultimate atomic form; and to show that the various forces by their mutual convertibility are but different forms of one universal energy.

ATOMIC THEORY. Tue ancient theory of matter pat forth by J)emcvitus, and prominently advocated by Lucretius, the Roman poet, supposed matter to be coinposed of infinitely small particles or atoms, which could not bo further divided. To give consistency to this indivisibility, the atoms were presumed to be infinitely hard. Without going into any detail it will be evident that by crediting the atoms with that quality, elasticity, which, is one of the properties of matter was ignored. The atomic constitution of matter lias, however, been revived of late years, but in a more philosophical form by Professors Helmholtzand SirWm. Thompson, the latter distinguished physicist being the author and leading exponent of what is known as the vortex-atom theory. Hβ supposes matter to be composed of excessively minute vortex rings of a. character similar to the rings of smoke projected from the cannon's mouth, or the rings of-condensed steam puffed by an engine from the exhaust pipe. The: vortex rings or atoms of matter are presumed to bo part of, and to move in that invisible imponderable fluid or ether, which scientists believe fills all space, and is the medium of the wave undulations of light and radiant heat from the sun. This conception of ring atoms i« well put by Mr. S. Tolver Preston as follows:—"Suppose a cylindrical bar of indiarubber to be rotated about its axis, and the bar (still rotating) to be bent round into a ring shape, and the ends joined. It will then be apparent that the material of the indiarubber ring may be in rapid motion while the ring itself preserves a fixed position in space." By this theory the elasticity of the ultimate atom 3 U secured, aa well as their indivisibility, while their motion being in a perfect fluid they can neither be generated nor deslroyed except by Creative power. •MOLECOXAR AGGBEOATION'. But whatever be the nature of these ultimate atoms, which can never be made appreciable to our sight by the highest power of the microscope, it ia assumed by many that in one or more forms and by their different manner of aggregation, under the attraction of cohesion, they compose the molecules of the various elementary substances, and recent researches render this probable. Although, even with these groupings of atoms called molecules of matter, we are dealing with such minute parts as cannot be rendered visible, we can in some measure appreciate their minuteness by thinking of the small portion of perfume which can permeate the air of a large apartment and render its presence sensible, or the tiny particle of colouring matter which can, when diluted in an enormous quantity of liquid, give a distinct tinge to the whole. In dealing with the molecules of matter, however, the man of science is not without definite knowledge, for their vibrations have been calculated by means of the spectroscope, and Sir William Thompson has approximately estimated their size and has assisted the mental conception by supposing a drop of water magnified to the size of our globe, in which case the molecules of matter would appear larger than shot and smaller than cricket balls. EFFECTS OF HEAT.

What then is the behaviour oE these molecules under tho influence of heat ? It is now generally accepted that heat is a mode of motion, whether in the form of radiant heat in the undulations of other, or as sensible or thermometric heat in the vibration to and fro of the molecules of all substances. This molecular vibration, whose amplitude is proportionate to the heat of tho body, would only cease at what has been determined as tho absolute but unattainable zero of temperature, 273ieg. Centigrade, or 459deg. Frhrenheit below the freezing point. On communicating greater heat to a solid body, the molecules have their amplitude of vibrations increased, the body dilates or expands, until the point or fusion is reached; here a certain amount of heat is spent iu overcoming the attractive force of the molecules, and bocomes latent. When the body is liquified, the molecules havo not only vibratory motion, but freedom of movement amongst themselves. Still further continuing tho heat, we reach a point where it is again rendered latent in overcoming the adhesion of the molecules in their liquid relation, and at last they are released and. fly off as gas or vapour. In the gaseous state they possess great velocity in straight lines, but while confined they are subjected to numerous collisions with each other. The velocity of their impact against the inclosing vessel constitutes their prosaure or tension. If additional heat be imparted, tho molecules attain greater velocity, and their pressure is increased if it be a compound gas or vapour, such as steam, dissociation takes place into its constituents, and poseibly by greater heat there would be dissociation of the elomentrry molecules themselves. The existence of a fourth state or condition of matter, in an ultra-gaseous form when subjected to extreme rarefaction, as recently advanced by Mr. Crookes, is by no means genorally admitted. ENERGY CONVERTIBLE.

With regard to the convertibility of the foroes of nature, a aubjeot which, as you are aware, has been treated in a masterly manner by Sir W. Grove in his work " The Correlation of the Physical Forces," the researches of recent yeirs have added much proof of a confirmatory character. We know that the mchauical energy expended in rubbing two bodies together is transformed into heat, and in ihe case of hard substances also into light. Tbut tho motion produced by the attraction of gravitation, say, on a falling weight when arrested the earth's surface, is converted into heat.' The relative value or mechanical equivalent has been definitely determined by Joule, lib. falling 772 feet, or 7721b5. falling 1 foot, producing heat which is sufficient to raise lib. of water 1 degree Fahrenheit. Agiiin, heat applied to the junction of two metals, such as bismuth and antimony, produces a current of electricity, and it, by passing through a wire of sufficient resistance, is reconverted into heat, and also by incandescence into light. By the motion of two heterogeneous substanoes against each other, as in the electrical machioe, wo produce electrical charges, which, by thoir attractions and repulsions, can emse motion, and by their uniting in the spark produce heat and light. Chemical action by combination, and especially in the union of oxygen with other substances in the phenomena, of combustion, is transformed into heat and light. la the voltaic battery by chemical' at fun on the more oxidible metal a current of electricity is developed which in its turn can produce chemical decomposition of a compound

like water into definite atom equivalents of hydrogen and oxygen, or decompose the metallic solution in. the electro-plater's bath. Light is capable of producing decomposition of metallic salts, as in the photographic plate, and both directly with platinum plates and indirectly by chemical action, can produce electricity. Electricity can produce magnetism, and magnetism can produce electricity, while it has an intimate relation to, and controlling effect on, light. Heat in the steam-engine is transformed into mechanical motion. Mechanical motion in the dynamo-electric machine can be converted into electricity, and that again into heat, light, chemical action, magnetism and motion. Thus, although we may bo ignorant of the nature of such forces as elec trlcity, we can convert one force into another even if in some cases with our present knowledge id may be necessary to make use of an intermediate step. Energy is ever changing either into active or dynamic form on the one hand, or seemingly lost, into potential form on the other, ready, by a change of condition?, to come forth again aud enter into freeh transmutations.

MATTER IN" LIQUID STATE. Coming to the work of the year, we find some interesting: results on the conditions necessary to the existence of matter in the liquid state by Dr. Carnully, and Mr. Haniiay, of diamondmaking celebrity. It is well-known that various gases, such as chlorine, carbonic acid, hydrogen, oxygen, &c, have been successfully liquefied by a judicious application of pressure, and subsequent codling by expansion.' The general opinion has been that solids liqnefiecl at temperatures varying with the pressure, that gases were liquefiod at pressure which varied with the temperature. But these gentlemen have shown, (Ist) that in order to convert a. gas iuto a liquid the temperature must be below a certain p.oinj;. (termed by Dr. Andrews the criticil ' temperature ' of the substance), otherwise no amount of pressure is capable of liquifying tha gas. 2nd : In order to convert a solid into a liquid-the pressure must be below a certain point (called by Dr. Carnelly, the 'critical pressure' of the substance) otherwise no amount of heat will melt the substance. Dr. Carnetty'a nret experiments were with mercuric chloride, but the most interesting results were with ice. In applying heat to it, while kept under the critical pressure no melting took place the ice was directly sublimed into vapour. In these experiments the vapour was condensed ia a. refrigerative vessel as rapidly as formed, to preserve the diminished pressure. B*t the most extraordinary part was his heating the ice while ifc was in contact with the thermometer bulb far above the boiling point of water, the temperature shown by thefchermometer being ia one experiment 120° C, or 248° Fahrenheit. To prove that the. ice was actually hot, it was dropped into water, nnd raised the temperature. The increase of pressure in the vessel during the oiperiment, instantaneously liquified the ice. This heating of the ice is, however, disputed by Mr. Hannay and othercompetent observers, who while able to sublime the ice without passing through intermediate state of fusion, have not succeeded in heating it beyond zero of the eintigrflclo scale. FOKMATIOX OF FOGS. The formation of fogs and clouds has formed the subject of an excellent paper by Mr. Aitken, read-before the Royal Society of Edinburgh. In it he shows that minute dust is necessary to the formation of fogs, tliafc these are not formed I by the combination of vapour particles, but that the vapour must have some solid or liquid body on which to condense.. Thus steam, and the vapour of all the substances tried when admitted to the vessel containing ordinary air, I gave a cloudy precipitation. But if the air was filtered through cotton wool, the vapours remained uncondensed, and gave no sign j of cloudiness. The fineness of this division of matter or invisible dust in the air, is almost infinitesimal. The motes of the sunbeam being coarseness itself compared with them. As an instance of the extreme test which condensation of vapour furnishes of the existence of this ijnat, the author states: "By simply heating a piece of glass, iron, or brass, a. cloud of dust was driven off which, when carried along with pure air into the experimental receiver, gave rise to a dense fog when mixed with steam. So delicate is this test for dust, that if we heat the one hundredth of a grain of iron wire, the dust driven off from it will give a distinct cloudiness in the experimental receiver, and if we take the iron out of the apparatus and so much as touch it with our fingers and again replace it, it will again be active as a cloud :pro ducer." The conclusions are :—lst. That whenever water vapour condenses in the atmosphere.it always does so on some solid nucleus. 2. That dnst particles in the air form the nuclei on which the vapour condeses. 3. That if there "was no dust, there -would be no fogs, no clouds, no mists, and probably no rain, and that the supersaturated air would convert every object on the surface of the earth into a condenser, on which it would deposit. 4. Our breath, when j it becomes visible on a cold morning, and every puff of steam as it escapes into the air, show the impure and dusty condition of our atmosphere. It having been shown that all forms of combustion, perfect and imperfect, are producers of fog nuclei, it is concluded that it is hopeless to expect that adopting more perfect forms of combustion than those at present in use, will diminish the frequency, persistency, or density of town fogs. More perfect combustion will, remove the pea-soup character from the fogs and make them purer and whiter, by preventing tho smoke which at present mixes with the town-fogs and aggravates their character." PREVENTION' OF SMOKE. As bearing upon (jhis subject, a scheme has been propounded by Mr. Monciief, for rendering London aud other cities practically smokeless. This contemplates making use of the plant -belonging to the existing Gas Companies. Butinstead of taking 10,000 cubic feet of gas from each ton of coal, if they were to take only one-third of that amount, and put through the retorts three times the quantity of coal, they woutd turn out the same quantity of gas as ai present, and produce a fuel -which would be smokeless, make a cheerful fice, and give out more heat than either coal or coke. Moreover, by the larger amount of by-products received from the retorts it woald be trore economical than coal. Dr. Siemens, who has invented a form of grate, by which almost perfect com.bustion takes place by means of gas and Coke, and who is an authority on the subject, says :— "I hold that it is almost barbarous to use raw coal for any purpose, and that the time will como when all our fuel will be separated into its two constituents before reaching our factories, and our domestic hearths. SPECTBOSCOPIC INVESTIGATION'S.

The idea Brst enunciated by Sir B. Brodie in 1567 as to the probable existence in remote time of simpler forms of matter in a gaseous state, rendered possible by the high temperature which prevailed,has been revived o{ late years bj the distinguished cpectroscopist and astronomer, Mr. Lockyer. As you are aware he builds on two grounds :—l. That there are different bands and lines to be seen in the spectrum of the same substance at different temperatures, and that those resulting from increased temperature are simpler, indicating a, dissociation of the body into a still more elementary form. 2. That there are short lines, called basic lines, which are common to the spectra of different substances. During the year considerable discussion has taken place on these varying spectra, particularly with regard to the carbon spectra, Professors Liveing and Dewar holding, in opposition to Mr. Lockyer, that the fluted bands aro really due to compounds or hydrocarbons, and that- in substances generally the different lines are harmonics of one fundamental vibration. That is, the same molecules are struck as a bell might be struck in different ways by the heat waves or the electric current pissing through them. Aa bearing on the first view, G. Ciamiciau has recently communicated BOino results of his investigations on the homology of spectra. With the group of earth-alkali metals, such as strontium, barium, ice, he obtained with the high temperature of the jar electric spark the lines in the lees refrangible part of the spectrum, and found a beautiful correspondence between them. On comparing these with the less refrangible part of the oxygen spectrum a decided resemblance or homology is shown. Again, magnesium has no lines in the lesa refrangible part of the spectrum, but if the spectra oE strontium or ba.rtam are produced with less temperature, say by a smaller battery and induction coil, then the lines in the red and yellow disappear, and the spectra which become visible are remarkably similar to those of magnesium. After showing that the atomic weights of barium, strontium, and calcium can be composed of the atomic weights of

oxygen. The improved means of fr.,?^ 4 spectra by the electric light andfihSSS'W has certainly revealed m the lines, requiring very careful an lfeS mveaUgatiim. But the theory which i-'-? 11 ' cuanees in spectra by increased UtopS^ 3 to the dissociation of the molecule*?? n ™ tion of the atomic grouping, siSfk e £ fe favour, and thus we mav have in ♦!,«•"■ " la as ia the organic ? SS oi an evolution theory leading froto sS tn more complex forma of matter. alln Ple to

FAMINE BEIATED TO SCJX SPOTS In meteorology Mr, F. Chamhi>r« \p «. r; the relationship which exists between*tS sun spots and periods of abnormal bam of both phenomena, resulting °f rO m W fal observation over mwiy years if iT t * found " that the epochs of mum barometric pressure lagged beMad ££ •poets: of minimum and maximum soWWtrf area at an interval varying from six rabJhifx two years and a-half, or an average and eight months." Mr. Chamblr, h« f«r?S shown that as the great famines of India 2 owing to the absence of rainfall,, and eachTf them was preceded by an exceptionally Li 1 barometer corresponding to iu* spot ponod, he reasons th.it /fattihesby thh means may be foreseen. Ho jams-aßsiM lows : -Ist. That variations of £ area are succeeded many months afterwards bv" corresponding barometric variations, 2nd TH? abnormal barometric variations travel at "a very slow rate round the earth from west to east arriving.at westerly stations several montß before they reach more easterly ones Tμ That famines follow in the wake 7 of wave,lf high barometric pressure. THE EARTH'S MAGNETIC PHESOMEXA Professor Stewart has made some suggestions as to the sustaining power of the. earth's magnetism and the probable cause of the magnetic variations and disturbances. Taking for "ranted that there U a inagnetic nucleus ia the .ear.Hr (which need not ba.large), he sees.in the sreii convection currents in the npper strata of tne atmosphere passing from theequatortothe pole* conductors moving across the lines of'magnetic f oree, and building up or strengthening theenrtW, magnetism. The diurnal variations he ascribes to changes in these upper currents influenced by the sun, and builds upon the fact disclosed by recant observations that magnetic changes like meteorological changes, travel from west to east, and lag behind the solar changes. Heaiso endeavours io account for the earth, currents I of electricity and the auroral displays; which are found to be invariable, accompaniments of magnetic storms, by supposing the e'arth to- be like a huge induction coil; the priinary rocks the moist surface of the earth, the lower strata of the air, and the upper strata being alternately insulating snd conducting media. ; Any change in the magnetic nucleus would'indoca currents in the conducting media corresponding in results to the observed phenomenal Acarefol comparison made during the year of photographic records from niagnetieal observatories has ehown that the disturbances in the .decline tion and horizontal-force needles are; produced at absolutely the same tiraa at widely distant stations throughout the world, and that' ; the direction is almost entirely the same. Fojntins as these do to a cause far outside of the eartti; there are eminent men who hold that by means of the etherial medium it is to the direct, action of magnetic subetanees, euch as iran in ttis sun ever being shot up in a gaseous state, condensing, and retreating again in those terrible commotions evidenced by the solar spots that we must look for the explanation of these raagnetic changes. ; ■ photo. electricity , . Professor Minchin has made knswn the results of his experiments on photo, electricity, his object .being—first, the prodnotion at a distance of effects due in the first instance to the photographic action of light; and, second, the continuous daily registration of the intensity of the sunlight, Bymeaneof two silver plates immersed in water, one of which, was coated with An emulsion -of sucli eubstances ■■ as chloride and bromide of silver, iodide green, with collodion j >&c., and exposed to the light, he has obtained, after eliminating disturbing currents, very decided currents of .electricity. These were generally from the unsensttised 'to the sensitised plate, and produced chiefly by the blue and violet rays. ECe also found that the currents produced by some of the emulsipns were due to direct action of the light, without the intervention of chemical; action. Plates of tinfoil in water, containing carbonate of lime, were intensely sensitive to light, and produced powerful currents. Dr. Kerr has. further ex r tended hU experiments on. tho action of magnetism on a beam of polarised light..■..'Hβ has passed the beam through' 3 large number of liquids under the influence of a strong electro magnet, and-in every case the plane was rotated, thus tending to give countenance to the theory that light may bean electrical phenomenon. f ':■,:■'. PROGRESS OP DrSASH) ELECTRICITY. '"-'"'

It is certainly in the domain of electricity and magnetism that the greatest activity-.is shown. Nothing can be more wonderful than the progress made every year in these tranches of physics, and especially their practical adaptation to the purposes of daiiy Hfe. Not only is there steady improvement on the discoveries of previous years', but the moat striking results are constantly being evolved from the hazy conception or laboratory experiment into the realm of useful application. Perhaps no better example could-be found than the transmutation of mechanical efiergy into electrical energy by the dynamo-electric machine. So long as we had to depend for powerful currents,on chemical batteries, wifh - their ' nnwholesome fumes, inconvenient and expensive arrangements, and inconstant strength, a formidable barrier existed lo further progress. It is interesting to note the growtb in practical application of the principle discovered by Faraday so long ago as 1831, that a awgnot can induce a current in the wire of a. closed circuit. All the powerful machines now in use are based upon this principle,, and consist of several coils of insulated wire, either adapted to a cylindrical iron armature or wound round the rim of an iron wheel, and vxa.de to revolve in the magnetic field of electro-mngnets. ■ Tho development of electricity by this means presents one of the triumphs of man's intelligence in utilising the forces o£ nature. From the small quantity of residual magnetism in the electro-magnets, oa revolving the armature and coils, a slight magnetism is induced in the one and current in the other. This current being led in whole or ■ £4 part round the • wires of the electro-magnets strengthens them and induces greater effect in the armature and coils, and thus, by action and reaction, with the increase of speed to-700 revolutions per minute, a current ia built up capable of producing a light equal to 15,000 candles. No doubt a great incentive to the perfecting of these machines has been the necessity fora strong and steady current for the ELECTRIC LIGHT. It will give some idea, of the intense coinpetition there is in connection with this form of lighting to state that no less than eigbty patents were taken out in Great Britain alone, In one year, for improvements in the procuction of the electric light. The large number of these light 3 now in use in Europe and America, in museums, halls, docks, factories, railiray stations, and other places of large area, hare established it as thorougly efficient and economical for suoh purposes. While the experiments made in street lighting, by means or Jabloehkoff, Jamin, and other candles, in the capitals of Europe, and particularly those now proceeding in London and New York,, will provide data by which to estimate its economical subdivision. The contracts let in London are three in nurabur, each embracing several streets, the systems adopted being Lontin, and Brush, respectively. In New Yor~ the systems being tried are Edison lamps and Brush arcs. Considerable success has attended the division of the current into a series of arc lights under the Brush and Werdennpn eystems. ■ - - .- , But it is to the further division of the UffS either for more equal distribution in «reet

. «• a or for more general use in ordinary Hgh tmmts that the chief efforts are now being T tei l For this purpose the incandescence indium wire in globes contam- ? EP fkicotobustible gas, such as nitrogen or a n w=°in° u particularly carbon filain vacuo, and i fc omise . The ment 3, f'aSxim and Edison, of New York, and {fTof New£sUe-on-Tjne, are on this prinS *f e ' the most recent step in advance being 2? hJdenin" of the carbon, to secure its lasting the o £ th a oharred Sf eOt " tof cotton or other vegetable fibre, of £ lame Aoe forrn andl connected with conducting horse-shoe jorm a withdrawn, 'if W» carbon gas is allowed to enter. On currenulroughthe fibre it is heated P XaVpontion of carbon takes place. The proW •« rnntinued until the resistance is uniform S3 tCC" badness is obtained. The gas is ?Ln withdrawn and the lamp is complete. Mr. (like Eduon) employs a vacuum in his Si His carbons are said to be hard and B i r« like steel and only one-hundredth of an f't;. thickness. On a recent occasion twenty Stotepswere effectively employed to light 1 tell, usually supplied by 70 gas jets consuming IsOcnbic feet of gas per hour.. The Dynamo Machine was driven by a gas engine consuming 160 mbio feet per hour. The question really Msolves itself into economy, but in any case Sere I , no danger of gaa being dispensed with. If we consider that the coirbustion of gas deSpl'e demand for it in the one form or the other. The trials of olectric lighting by Dr. Siemens for hastening the growth and development of flowers vegetables, and fruit have been further prosecuted during the year with the most successful results. ELECTRIC TORNACES. A new source of usefulness is opened up by the application of the electric arc to tho fusion of refractory metals. Experiments have been made with great success by the last-named scientist ia the melting of steel.. It was found that lib of coal used in the boiler of tho eDgine driving the Dynamo machine sufficed to melt m> of Bteel in the electric furnace. The first | oast was made in fifteen minutes, the second in eight minutes. By. this means, the heat is almoit unlimited, while it u> economised by direct application to the metal whish, in this case is hotter than the crucible. Already, a company is .projected in America to treat metallic ores in this way.

ELECTRICITY AS A MOTIVE POWEK. Bat perhaps the most important application of the currents produced ty dynamo electric machines is to the transmission of power. The current generated by one machine, driven by a stationary steam or gas engine, can be transmitted by an insulated conductor to a distance of several miles, and produce rotation and develope power in another dynamo machine, by rererse action. As you are aware, experiments iave taken place in ploughing fields by this means. Daring the year, further experiments iave been made by M. Ffclix, at tho Regional Agricultural Show, in France, and also by other gentlemen, with complete success. M. Menier at Nossial, used a six-furrow plough with 18 horsepower available. The electrical railway in use rat-the Berlin Exhibition, showed its applicability for locomotion on short lines. At present it is proposed to erect a permanent overhead tramway in Berlin, to be worked by electricity, and at the forthcoming electrical exhibition ai Paris, the same form of locomotion will be introduced.' Among the advantages of the system, "there are the absence of smoke or .traction ropes, the maximum of power is exerted on the dynamo machine on the carriage when the motion is small; hence ic starts with great energy. F.or the same reason the lessening of speed in ascending hills brings more power into play.' It has been found " that the proportion of power transmitted actually reached a maximum when the machine on the train has velocity of two-thirds that of the current-generating machine, at which time more than 50 percent, of the power of the stationery engine is actually utilised." The facility with ■which electrical energy/can be transmitted, and the large proportion of power which can be got from a good dynamo machine, point to •electricity as destined to play an important part in the motive power of the future. About 90 ■oer cent, of the power expended in driving tte machine ie reproduced for work; whereas in a large and efficient steam engine, by reason of unconsumed carbon, loss by radiation, conden- ; sationj and friction, not more than 20 per cent, of the heat energy applied in the furnace of the steam boiler is available for actual work in the engine. With a small engine the result would not be more than one-third of that. So that we may yet see large central heat engines distribnting power economically by electricity as gas 13 now supplied from a gasometer. But it is evident ttiat still greater economy would result if instead of a.heat engine we could utilise the forces of nature at the distributing station for producing electricity. Hence attention has been directed to-waterfallsj rapid .steams, the rise and fall of the tide, as_primary sources of power. From estimates which have been formed it would seem that the potential energy-- of a tidal rise of 10 feet sach as the minemum in Auckland harbour would give about one horse power for every 1650 equare: yiurds of Bea surface, even if only 25 per cent of the power were utilized. Doubtless meane will yet be devised of laying this enormous natural energy under contribution to the wants of man. Already there are several instances in Eo-rope of waterfalls being used for the production of light -and mechanical energy by the agency of dynamo machines. It is true that one of the disadvantages of electrioity is the imperfect manner in which it can be stored up "for use, so that the cm rent has to be used as it is formed. To this it may be urged that the same machine current which would be required for power in the daytime could produce light at night, or the current could be employed in dissociating water into ita constituents and storing up the oxygen and hydrogen to developo heat by tboir union when wanted. Then there is the secondary battery of Plante, tbe lead plates of which can b* polarised or charged by the machine to an extent depending upon their size, while the new storage battery " of Professors Houston and EUhw Thomson, of America, on the gravity principle, will doubtless be adapted as moderate sources of power. Thus, for the small machinist ai driving power, and for the sewing machines of the factory and the household; we may yet see a charge of motive power supplied to a secondary battery, just as in London the consumers cisterns are periodically supplied with water. TELEPHONES AM) THETR MODE OF ACTION , .

The use of. the telephone has been considerably extended by the establishment in large centres of population of the 3yatem of telephone exchanges." Amongst - receiving instruments, the Gower Bell Telephone has taken a decided lead, as regards loud speaking and efficiency, while carbon or microphone transmitters, of various kinds, have come into general The disputed question as to whether the "sound produced in the receiving telephone is dae to vibrations by flexure in the diaphragm, or to the molecular changes in its substance, has.received further elucidation, bpeech has been produced in the telephone with thick plates of metal or discs of wood, when substituted for" the thin diaphragm, and also :without any diaphragm. There exists Ihttle deubt now that the sound is due to the minute changes in the molecules of the magnet and diaphragm, produced by their magnetisation and de-magnetisation. Considering tfaat tne currents produced in the telephone coiifl are barely appreciable by the most sensitive gal- | vanometer, and are estimated to be only one j two hundred thousandth part of the current from a Daniel's cell, or equal to what such a current would be after, passing t h j° u p 6,200,000 miles of telegraph wire, and the minute change which must take place in trie molecnles of iron under the magnetic influence, we must be struck with wonder alike at the minuteness' of the pulsations of air necessary as a medium to convey' the sounds and the extreme delicacy of the human ear to be able to distinguish them. ■. ~ THE LN'DUCTIOK BALANCE. As we often find, one invention leads to another and the telephone has been fruitful in this respect. It led to the delicate induction balance of Professor Hughes, wherein two equal coils of fine "wire form the balance. Xhe -Bubatance to be investigated is placed in one of these "coils, by its - presence it modifiee ; the induced currents passed through the coilß, a. telephone being placed in circuit at once detects : the change by. the sound produced. But instead 'ofoosnectingthe telephone directly with the coils he completes the apparatus by a none-

meter, which is simply two coils, one at each end of a graduated rod connected with the balance. Thus far the sonometer is like a dumb-bell the weights at the end representing the coils, the part srasped by tho hand ,representing the graduated rod, on this graduated part another coil connected with the telephone is made to slide to any position relative to the two fixed coils. The result is that whatever may be the difference of weight or of substance in the coil or coils of the balance and the consequence disturbing sound in the telephone, by sliding the moveable coil as we would a weighing machine indicator, we get a point where the sound is nil. This point indicates the difference of weight and the nature of the substance. By this means a difference of one part of alloy in 10,000 parts of basic metal can be detected. If a good coin is placed in one coil of the balance, and a counterfeit one in the other, it is at once detected, and the nature and amount of tho base metal accurately shown. ACTION OF ELECTRICITY ON MAGNETIC CON'DTJCTOBS. ■I have been thus particular in describing the ingenious application of the telephone in the induction balance with a view to the more clear understanding of some very interesting experiments which have just been made by Professor Hughes on the behaviour of magnetic substances, such as iron wire, under the influence of elastic torsion and electric current?. These have thrown some light on the nature of the action exercised by electricity on the structure of bodies. In these experiments he used a sonometer, which thongh differing in form was substantially the same in principle as the one described. But he added a beautifully simple and effective arrangement which he calls an Electro-magnetic Induction balance to distinguish it from the other Induction Balance. It consists of a small coil of wire placed on its edge in the centre of a board. The iron wire to be operated upon is made to pass through the circular opening in the centre of the coil, and thus to form a detached axis. One end of the wire is fixed to a support at one end of the on board, the other end of the wire, while reeting the opposite support, is free to receive an elastic twist. A copper wire attached to each end of the iron wire completes the circuit with the sonometer nd included. Now note what takes place. On parsing an induction current through the coil no eSect is produced on the iron wire passing through the axis, because the wire is at right angles to the current, or in the position of no effect. If ho turned the coil a little so as to alter this relative position, a current would be produced, as is well-known, of a secondary character in the conducting wire. But instead of altering the coil, he gave a twist to the wire without changing its position. A sound was at once heard in the telephone, showing that a current was passing in the iron wire and the movable coil of the sonometer. Thus a primary or tertiary current was produced purely by twisting the iron wire in a closed circuit without a battery. To what was this current due ? Professor Hughes answers.:. It is due to a molecular magnetism, which, he distinguishes from the ordinary molar or longitudinal magnetism produced in iron or steel. The elastic torsion to which the wire is subjected alters the molecules on the outside so as to make them no longer perpendicular to the centre of the wire, and they produce a current on the wire as magnets would on a detached wire. If the experiment is reversed, and the battery current sent through the wire, the coil being connected with the telephone, and the sonometor brought to zero, on giving a twist on the wire sound was produced from the increased or diminished etrength of the current. Bat we come to another remarkable result. He found that on passing the current from the battery through the wire even for the one hundredth part of a second, it produced a permanent molecular twist. If the direction of the current is reversed, the twist is the other way. Although 40Jeg. of mechanical torsion is required to undo this twist, nothing is visible in the wire itself. Indeed, the two ends.of the wire being fixed, the molecular twist is still produced by the current. By heating the wire or putting it into vibration for n. few minutes, the strain is reduced. But the application of a magnet causes the strain to disappear instantaneously. In Ampere's beautiful theory, magnetism is simply the polarising of the..molecules, so that the electrical currents circulating round each is made uniform in direction. But, on the above results, the professor remarks : " It will be seen that the molecular arrangement set up , by magnetism is very diiferent from that produced by the passage of electricity." Analogy would lead us to expect that some similar effects may be produced on non-magnetic conductors, and although Professor Hughes hae not found any strain produced on them by the current, yet his well-establiahed ingenuity will no doubt bring out important results in this direction. THE PHOTOPHONE. The most remarkable event of the year in connection with the telephone is the discovery of the photophone by Professor Bell. The principle underlying this invention, namely, the change of resistance to the passage of electricity, which tskos place in the metal selenium by the action of light, has been known for many yeirs. It has been experimented upon by many scientific men, notably by Mr. Willoughby Smith, Professor Adams, Lord Rosse, and.Dr. Siemens. Tho latter gentleman constructed a cell, which only gave one-fifteenth part of the resistance when exposed to light, that it gave in the dark. Lord Kosse proved that it was light, and not heat, which affected the selenium by passing the rays through a cell containing a solution of alum, and thus shutting off the heat rays. Even in 1878 experiments were conducted with thi3 substance, having the telephone in circuit, and Mr. Smith heard sound produced by light. But it was reserved for Mr. Bell to solve the problem of transmitting speech by means of rays of light. He found that the most sensitive state to light was secured when the selenium was heated till it formed a grey crystalline mass and was allowed slowly to cool. It is then applied to the cell in thin layers between brass discs, joined up alternately to the poles of the battery. But the essential part of the invention is the means whereby the undulatory waves necessary to speech are scoured. The mere rapid intermission of the light on the cell will only produce musical tones. For this purpose he uses a silver reflector of thin mica which is flexible to the sound waves directed to its back by the voice. The rays from the sun or other light source are reflected from the face of the mirror to the distant station and received on the ielenium cell, which is placed in the focus of a conical mirror, and connected with tho battery and the telephone. The minute wave variations of light produce corresponding changes in the current which are audibly distinguished in the telephone. Speech has also been prodnced by Mr. Jamieson through the agency of a gas-jet inclosed in a glass tube, the membrane spoken against varying the supply of gas and causing changes in the height of the flame, which are reflected to the distant selenium cell.

MUSICAL PHOTOPHONE. Professor Bell alao introduced the muaical photophone, in which the selenium cell is not used, but discs of metal are subjected to the rays of light after passing through a perforated diec in rapid revolution the pitch of the sounds varies with ths rapidity of the intermission. Nearly all ,Bubstances were found to produce this effect, aed Professor 801 l thought that he had found some new affection of matter. But later researches by M. M»rcadier, Professor Tyndall, and Mr. Preeco, have proved that the effect is due to radiant heat. Professor Tyndall has Bhown that the rapoure from a large number of liquids, such as water, sulphuric ether, ko., give forth loud sounds in the telephone in proportion to their absorption of heat. That is those which, ate athermanous produce moat sound, those which are diathermonous least sound. On intercepting the heat rays from the former the sound ceased. But it is to Mr. Preece that we are indebted for exhaustive experiments that have set this point at rest. He found that ic was to the vibrations in the air of the cavity, "> whioh the diacs were placed, that the sounds -were really due. Sound was heard m the ear,tube when the disc of metal was removed, and a class lens interposed. The effect was heightened when the discs were coated with larop.black on the outside, nest the radiant source, thus increasing their absorption, and it wne necessary to.blacken the back of the cavity with lamp-black to obtain Bound from dry Mr. The question then arises, how are the vibrations caused in the air of the cavity—are they caused by vibrationn in the plate communicated to the air? The delioate microphone -when attached to the plate awwers, No.

The rationale is as follows: The discs absorb radient heat, it is transmitted te their inner surface, where they radiate it across the cavity to the absorbent wall, the particles of air striking against this arc, heated, that is, the velocity of their vibration becomes greater the air is expanded and the tension increased, the intermission of the rays by the perforated disc again diminishes these, and the repeated expansions and contractions of volume produce sonorous eflecte. Aβ a reason why snioke and the vapour of water pioduce greater sound when mixed with air, it is suggested that the smoke particles, or the molecules of the campound vapour being larger than molecules of air, are more readily affected by the wave undulations of the ether, and thus receive thermometric or caloric lieafc motion, and by staking against the air molecules their vibration is also increased. The same effects as were produced by radiant heat and a perforated disc were also produced by a platinum spiral enclosed in the cavity, through which was sent a rapidly intermittent current of electricity. The rapid changes of heat caused a series of expansions in the air, and loud sound was emitted. So effective wos this that when used as a telephone receiver speech could be perfectly heard. SEEING BY ELECTRICITY. Before leaving the subject, I shall only briefly call attention to the development of the principle of the photophone, by producing a photograph of a distant object by electricity. slr. Shelford Bidwell has succeeded in procuring a counterpart of an illuminated image thrown upon a revolving oylinder, in wliich is a small opening, allowing the light from successive parts of the image to impinge upon a selenium cell inside. The varying currents thus produced exercise varying effects on a sensitised paper upon a corresponding cylinder, which revolves synchronously at the other station ; To this process ho gives the name of telephotography. Professors Ayrton and Perry have also successfully produced similar effects, which they have termed seeing by electricity. They use for this purpose a very ingenious valve or trap-door in a tube, through which the light is thrown on the screen. This valve ia turned by means of varying currents, passing through tho selenium cell at the other station. The light at tho receiving station, being admitted in greater or less degree, pro ducea corresponding effects on the sensitive screen. Thus one discovery follows on the heels of another, and this last invention doubtless contains the germ for further development and useful application. CONCLUDING REMAKKS. I have thus attempted, necessarily in an imperfect manner, to give a resume of the subjects which have occupied the minds of scientific men in some branches of physical science, with" the conclusions arrived at, and the progress made during the year. With the ever increasing refinements in the instruments at his command, the natural philosopher is enabled to attain a delicacy, an accuracy, and a range of results impossible to his predecessors, but with extended scope and wider generalisations there come new problems to solve, new mysteries to unravel. "Vast and comprehensive as is the knowledge acquired in every branch of science, what is known is but an infinitesimal portion compared with what there ia beyond, while much will ever remain inexplicable to the finite faculties of man. But in seeking earnestly and fearlessly to know the sequence of events, the relationship of things, and the mode of action of that all-pervading energy which it has pleased the Creator to impart to the existing universe, there is no necessary connection with Atheistic principles or Materialistic philosophy. On the contrary there may (as in the case of the late distinguished Professor Clark Maxwell) exist the most profound learning and scientific genius, with Christian humility and enlightened reverence. Let us ever remember that in the field of natural science, apart from the ameliorating influences that follow in its train, it is the pursuit and attainment of truth rather than its possession which affords the keenest enjoyment. Of the scientist, too, it may be said that, leaving the things which are behind, he reaches forth to those which are before, assured that with increasing knowledge there will ever be opened up fresh avenues of investigation to stimulate his zeal to exercise his powers and minister to his mental delight.

If our Institute be successful in inspiring and maintaining a taste for the acquisition of learning, and encouraging habits of observation and thought among its members, then will tho sense of its importance and the height of its aims grow with tho growth of the community, and in its career of ussfulnesa it will be privileged to assist in laying the foundation of accurate knowledge concerning the natural history and traditions of our adopted country, while exercising a healthful and elevating influence on succeeding generations.

Golden Plover.—Mr. T. F. Cheeseman read a paper upon the existence of tile Golden Plover in New Zealand. The specimens exhibited were shot by Mr. B. A. Plumley in Manukau harbour. The President said Mr. Plumley had been kindly attentive in forwarding interesting birds shot by him to the Museum. He hoped that other sportsmen would follow his example. Carabidje.—A paper by Captain Broun on the New Zealand Carabidce was read by Mr. Cheeseman. It was of a strictly technical character. A Pest.—Mr. Mackechnie exhibited anew kind of insect, which covered his furze hedge. The branches were specked white with the insects and their ovaries.—Dr. Purchas said this was an insect which he had already brought under the notice of the Institute as having destroyed his hedges of kangaroo acacia. It was described by Mr. Maskell in vol. 11 of the Transactions of the New Zealand Institute. The name of the insect is " Icerya Purchasi." Sale of Books.—The President said that as there were duplicates of books in the library, the Council had decided to offer some of these duplicates for sale. With the proceeds other books of an important character could be procured. Thanks.—On the motion of Dr. Purchas a vote of thanks by acclamation was passed to the President for his address. This concluded the business of the evening. The next meeting will be held on the 11th of July.