TRANSIT OF VENUS.

Otago Daily Times, Issue 4023, 9 January 1875, Page 5 (Supplement)

TRANSIT OF VENUS.

DINNER TO THE OFFICERS OF THE FRENCH AND AMERICAS EXPEDITIONS. The dinner given last evening by the members of the Otago Institute to the officers of the French and American Transit of Venus Expeditions, was remarkably successful. Seventy-six gentlemen; of whom only twelve or thirteen were non-members, sat down to an excellent dinner, provided by Mr Hetherington, of the Shamrock Hotel. The President of the Institute (Mr J. T. Thomsop) occupied the chair, and was supported on the right and left by Professor Peters and M. Boquet de la Grye and the officers of the French and American expeditions, and of the war ship La Vire, His Honor Mr Justice Chapman, and the liev. Dr Stuart. Captain Huttou and Messrs J. S. Webb and M'Kerrow acted as croupiers. The following letter from His Honour the Superintendent was read :— "Superintendent's Office, "Dunedin, 7bh January, 1575. "Dear Sir—l much regret being unable to avail myself of the kind invitation of the Fresident and members of the Otago Institute to be present a.t the dinner to-morrow to meet the officers of the French and American Transit of Venus expeditions. " I nesd not say that 1 look upon the occasion a3 one of very great interest indeed, and that, as political head of the Province, it would have afforded- me much pleasure to liave been present, and on behalf of iho people of this small section of the British Empire to have conveyed to our French and American friends our earnest hope that the three great nations may long continue to go hand in hand in the pursuit .of scientific research—that burying the animosities of the past they may evermore remain united in every enterprise which is calculated to promote and extend the happiness aad progress of humanity. '' I remain, dear sir, "Yours faithfully, " J. Macandrew. " J. T. Thomson, Esq., " President Ofcago Institute." After justice had been done t6 the dinner, the following toasts were duly proposed without speeches:—"Her Majesty the Queen," " The President of the United States of America," " The President of the French Republic," "The Prince of Wales ami the Royal Family," " His Excellency the Governor," aud "The Army and ]S Tavy." The next on ihe list was the toast of the evening—"The American and French Expeditions," —in proposing which The Chairman said : Great contrasts will present themselves to the mincis of many of you this night—that is, to sucli of you that can east your inind3 back for thirty years and call to memory the savage nature of"" theso islauds at that period. I can only count a residence of little over half that time, yet I found things sufficiently primitive even t ien. Thus, His Honour thoSuperintendent, who w.is to sit by me here, might have recollected his six weeks' voyage to Invercargill, whtn he found me camp-ad Jn the bush that then occupied the centre of Tay street. He reached ni3 pretty well fagged and starved after being engegejrin cutting h>s way thioigh the Tautuku bush, subsisting on fern roots and the twigs of tress. Such is the experience of those who are not very old sutllei-d. To-night we. sit down with iiueliiyent arvd leirced n!>rfrom the most scunii&c circle* of. Eiuope and America. If we ask ou.r*e.\'es what brought most of us here— tliis most remote corner of ihe earth— we for ifte most part will coafess that the motive h s bjen self-interest. We now meat together to do hcaiour to our friends for the reverse motive of action. They come here with no views of self aggrandisement, but in pursuit of an enquiry that now engages the jitteution of the mo3t scientific men of the age. It Uaa enquiry that taxes the ability of the most profound astronomers. The pursuit is cairied on for the most part for the love of knowledge jaloae—but as knowledge is power —so hi the gra3p of t)j.e learned and thss humane, it will be used for the ultimate good of mankind. The object of our friends' visiab, 33 you all know, was to observe the traiisifc of the planet Venus across the disc of the Sun. This having been obtained iv conjunctioit with many other .expeditions in various parfca of the world, vCliita are thus had for calculating-*:-Ist, the Bun's distance from our Earth; and Ecd, t&0 : distance of all planetary objects iv our solar SVfctera. Bst I must not intrude on the ' peculiar arena of our friends. lam not ,ecißp.e£fcnt Jo do ithja j yet I may remark that is all momentous gfudies there is a division of labour—and here £l£o we have that division. The mechanician and optician 4o their parts ; and as a surveyor, f. may filfAm that we do ours also in the trigpnonittrj.e,<j,£ branch of the profession. To solve fcjje p'cobjiem w.e have Jhe observations of $he astrononie?3 ou the parallax, and the jueasuveuients fifths trigonometrical surveyor for the base. Sow, to give you a comparative notion of the ijiagnitude of ihe respective .portions of labour of the a tronomera' parallax of distance j Let i£ he said to be as the length of this hall. The surveyor's base ceuld not e^eped the fc-rgadth of a small needle. What a toiling , par* falls to the surveyor, I imagine I hear come at you cry. Not so, gentlemen; the .surveyor's J.>ase and deductions stretch across jthe diameter of this earth of ours, and the tabulations ,of its various proportions astroftoinejis wiU even admit to be extremely complex and y.aric.d, calling for thp services of the jnosj; asute inathe.niaticians. Thg?, Jhe structure]} .of li.atiar^, whether in their gjgg.n.« teaque or Riisrossopi,? pljss.es, are b.ehefd by ; the mind of man by relation #fld approxinia : lion only. By his reason alone he hag not jrej; reached the infinite either in expansion of contraction, and I am not one of those who can be convinced that he will ever do so. The diameter of the world astronomically—this needle's breadth—thes, has engaged the attention of trigonometrical Bur- . yeyors for more than a century. The Peruvian «s,rji was measured by Delambve, the English py Koy, the American by Mason and Uixou. Since "theijE- tjine arcs of the meridian have been measured i/i Sweden, Italy, Germany. !\»d Russia. But the operations with which J. aej. best acquainted 'are iu/jse of British Jn lia. The3e stretch f ioin Octna fiorajprin to the Hjoialays, Mountains, over''2G* degrc.es of latitude, and in length about 9,432,8<00' feet. This {to my knowledge) j;s. by far tbe. greatest work accomplished in th.c ri-ij-oction pf measuring a chord of the eaj- th's n).eri4i.»n eujrface ; that by Strauss, in Hussia, extendpg'only to 1,309,742 feet. Thia earth of pura theij, by the measurement of trigonomeJCriyal kavypycvg, ha.3 been proved in all its proportions.; and on/j main fact in all these js that it i 3 npt ro.un,d, biyit that it take 3 the gbafte of an obiute spheroid, with §, compression ftt tne poles-en ualtj 28 mile's nearly. Thua the ftstiipnomep, Jn Jj.is profound enquiries, avails' himseJl of thoae fjrduona «iiti intricate i mea&uren>ents of th.c t^gu^m/jtr^cal survey, '■ ixti&O- he indicates by hi 3 uupi.irajilejefj. skill' th@ distfljice from us to that mighty orb i •which rulea our l)i.'mament. But 1 hasten to the more immediate objocb of the toast of« the night. Our learned guest from America ■js well-known in astronomical circles. His of light had even penetrated to this "dark corner, for his fame ha 1 preceded him. In Europe he WS3 associated with the celebrated Eucke. JHe kimsejf had discovered more planetoids—iv number, J balieve, 19 or gO-»-than any other a'strbnmijei^ ajid to whicij. may be added three ciimetp." Further, ; lie ,aew giwes hjs valuable services to the Transit of Venus Expedition -withput fee or emolument.. Thisiswhal; \ call devotion toan >liustj'ious caus^. I may say tiiafcl h.fjvereason to ba pceuiiarly grateful to him and his staff, as it was through the encouragement gi hi 3 principal assistant, Lieutenant Bass, £hafc ?ny friend M'Kerrow and self got connected vith the enterprise,-and as au integi'al V>6rtion th.eroof. And, though duty required fhat" we" should attach ouvselves to the exoedition seiit out from our own natiop, yet \t w.as Mr Bass's encouragement that led to this. To our scientific guest- from France I turn with great pleasure. He is also a man of mark, having eondugted allied and cognate labours in his yery extensive hydrographic surveys of the west coast of France and New Caledonia, and in the compilation of nautical directories of the same. His genius and energy w§re also conspicuous in the defence of Paris, the capital of France itself; and his inventions o f arms of defence are also favourably known in the mechanical world, the personal intercourse that I have had with him impresses me with the highest resDCct for his profound knpwledge and practical familiarity with the ingenious qnd delicate instruments used in astronomical obserVfltiojw. Now, though, out friends from

i America carry back to their country a store (or, in diggers' parlance, as they were stationed in a gold mining district) a pile _of I scientific wealth in the observations which they, by the favour of Venus, have secured ; yet let us not less value the labours of our French friends, for they struck out boldly for a greater prize, which the high latitude of their station would have secured to the world. That they failed m their object was I not their fault; this i 3 due to the wellknown freaks of the fickle goddess. Gentlemen, I now ask you to drink to the very good healths of iJr Peters and M. Bouquet do la Grye, and the members of their respective staffs. Professor Peters, who, in rising to reply on behalf of the-American Expedition, was received with loud and prolonged cheering, said their worthy President had begun his speech by going back 30 years, but he (Professor Peters) would go a little further back, and begin at the very beginning. Although they need not be afraid that he was going to make a very long speech, he would begin at the very beginning, when New Zealand made its first appearance in history. The historical record of New Zealand began with an astronomical event, exactly similar to that which had given the occasion fer their intercourse to-night.—(Applause.) To observe the transit of Venus in 1769. Captain, then Lieutenant, Cook, wag sent out to Otaheite. He there became aware, from a Native tradition, of the existence of a large unknown country in the South, and after having accomplished his work at Otaheite—having successfully observed the transit 'of Venus—he started in search of the continent, and found New Zealand. He circumnavigated New Zealand, and from that day New Zealand existed in history. —(Applause.) One hundred and five years had passed away since then, and how much had changed upon the surface of the Earth !If an inhabitant of Venus was endowed with sight powerful enough to watch the doings and workings and movements of mankind, and exercised that power only at those intervals when Venus came midway between, or in. the same lino with the sun and the earth, would he not be astonished in 1574, when he came to Jnok again upon the samespots that he saw in 1769? He would see beautiful cities where beforo he only saw wildernesses. He would see that the civilisation of Europe had gone through the length and breadth of a country which was then inhabits! only by the Maori. He would see arts and manufactures of all kinds established in a country where, when Oopk sailed along its coasts, he saw nothing but the poor simple children of nature; aud perhaps that same inhabitant of Venus might also ca^t a glance at Lake Wakatipu—(ap plause)—and remark there a little party busily engaged looking at Venus and the sun. And ho (Profo33or Peters) would wish to tell them in a few wopds what that little party hid accomplish d on the shorgjs qf the beautiful lake at Queenstown. —(Applause.) He would do so at the suggestion of their Chairman, because he knew that a record of astronomical observations atadinner party was rather, a dry story. As all present wsre not astronomers, in order to bo understood he must make a few introductory re marks. The problem which they had to solve by observations of the transit of Venus was the measurement of a very small quantity—to the measurement of a small quantity by means of two large quantities. Let them suppose two astronomers, one at the centre of the earth, and one at the surface of the ear;h, looking at Venus when she was nearly in the direction of the sun. Tne observer at the centre of the earth would see Venus at a certain point; aud the observer at the surface, if not exactly in the direction from the centre of the earth to the sun, would see Venus a little displaced in another point;. it was this difference, or this displacement, which had to be measured. He said " the centre of the eq.rth," but of course no one—not even their daring friends of the French expedition—weuld venture to go there. Therefore they took two observations —one in the Northern and another in the Southern Hemisphere, and observed the displacement in regard to the sun's centre between those two ppjnl s. The further apart the better, and therefore the point 3of observation were extended over as wide a range as possible, and not at that point where Venus was in the zenith. For that reason everyone tried to get as far away ss possible from that point in which Venus was in the zenith. For that reason, also, had the French s.clepted their station in the very centre of the southern polar regions. Now, the question was : How cou}d they measure ihe displacement upon which all depended, as their chairman had explained — the parallax upon which all depends:!-.—in order to measure the distance between jbhe sun and the earth. In former times—in the lagt century—when the previous observations of the tr.&nsif; were taken, there were no other means available but to follow the rules of Halley or De Lisle —to measure the time when Venus would be seen in contact with the sun—when the iinif}3 t.pupl^ed either externally or internally. Since that iime ptiier sciences had come into existence, and as eye*y goignce helped the othera, thege sciences helped astronomy. For instan c, they now had photography) jjnd when the time was approaching that the transit of Venus should again take place, one of their first ideas was to make use pi photography to determine this small displacement, He would explain how the measurements of phonography stood in regard to the form.er measiir.empntg. It was qegesgapy to mark £he ej:act time wJjen Venue's cen^i-p was a certajii'distance from the Sun's centre, Let tlr gf suppose the Sun's centre and Yonus's were in a vertical lifte--then the displacement would be such that the distance of the centre would be-either shortened or lengthened according as the observer stood in thenorthern orsouthern hemisphere, If yie£us and the s>un were on the same eleyatipn afyo^e $he horizon, the parallax would fetjl the effect iv $o|; being shortened to any considerable extent—is. fget, the disfcjnpe would not be affected at aIT, but £t would hayjs s.n ejTect upon the angle. The | gieatest i fleet wouj,d jbe upon the angle ; and they had the means flf' compuzing-'thp ai}g]3 which the line from the sun's pentre to Venus's niadg with a certain given line upon the sphere.. Thi§ displacement W as formerly measured alone ; so in the contact they observed how much longer one party observed Ihe contact after another. If photography had been applied, the distance would have been measured on a photographic plate—the distance of the augle of position. They saw, therefore, that by photography they had got the means of multiplying im'menßpJy one observation of the contact, and'one observation by photography equalled, under the same cjrcumstanc'ea, on.c contact, Therefore, the American "expedition directed th.eir £j£or{;s to make the photo.graphic observation' as perfgep as possible, and considered the contact observation, only as a confirmation, ov rather as an observa.tion necessary for examining sertain physical phenomena connected with the contact The prinriparphotographic apparatus was a ltsnse of Jjin. p.perture, aud 40ft. focal distance, without (j,ny magnifying lense between. The image of the sun jji this lense, as could be easily seen, >vould "6e about 4^in, aucl the image of Venus would be aijoutone-^rti^thof an inch. was peculiar in the American instruments was this s tliftt thpy not only measured the distance, but also measured the angje of position,. They did not find the effect simply in the distance of the centres, but also in the direction. He believed no other nation had a similar apparatus. He believed that next to the American system came the French. As far as he had ascertained, he did not believe that the English, Qermaus, or Russians had photographic instruments' as • perfect as the Americans and French. " He bejieyed, therefore, that each of the America^ phonographs would be superior to .each ope ot the photographs taken by the other nations mentioned, The measure of angular position, however, w.ij,a peculiar to the Americans. He would no\y tell them how iflftny observation* his party had taken. They had got about 299. —(Applause.) From 'that number, however, would have to be deducted over 60, so that of useful observations there were §§7- —237 measurements of one contact. He had to "be gKpliaifc on this point, in order not to depreciate $he observations !!o,f his party. They had not relied upon'the con-! tacts. He had' heard it saidj and he had i s.een jt seated in the public Press of New Zealand, "that the "Aineric'ari party had pnly got one-half of the observations, because ■ they had observed only one contact. That was quite a different affair. Besides the photographic observations, they had also taken direct observations of Venus, in order to examine especially the physical phenomena of the contact; and they had, also, at the same time, obtained a series of measurements which would give actually the moment of ingress. After explaining thtt he had so arranged the contact observations, n prder to gain, a. ffarther ftd,van.t%e ja gon-

riecfcion with the measurement of the solar/ diameter, -Professor Peters went on to say, that, in order to give his audience an idea of the srnallness of the angle they wanted to measure, he would ask them to picture to themselves an angle formed with a human hair. The angle which they had to ascertain was equal to an angle formed by a hair ext.nded at a distance of SOOOft. They had to measure the thickness of a human bair at a distance of 8000 ft. This was the first time in history that the United States had participated in an observation of the Transit of Venus ; this was the first time that the Transit of Venus had been observed in New Zealand since it's discovery in 1769. His party felt that they could not have accomplished what they had if it were not for the great kindness they had met with ia this country. They had received aid from the General Government, from the Provincial Government, and from numerous private friends interested in science, and they were indebted in every way to the citizens of QueeDstown. They would leave this country with a deep feeling of gratitude towards its inhabitants. They did not alone deserve praise for the success of the expedition—their New Zealand friends deserved an equal amount of praise. Professor Peters then resumed his seat amid loud applause. M. Bouquet de la Grye—the chief of the French expedition, who addressed the company in his native language—then said : After the amiable and complimentary expressions of the President, I must say I feel somewhat confused. I thank the members of the Institute for the cordial reception accorded to myself and my countrymen in Dunedin—a reception which bears testimony to the interest tsken by it in the astronomical question which we came here to determine. We came here to determine a great Question—viz., the distance of oar poor globe from the body to which G-od has given the attribute of conveying us light and heat. My friend who has preceded me—the chitf of the American expedition—has had the happiness to meet with complete success, and has been able to attach his name to a successful elucidation of this question. Mr Peters has met with such complete success tliat there is no need of other observations— he has accomplished all that was to be done. Two montf s ago scientific Europe was awaiting with anxiety news from the most distant stations, a fact which is testified by a letter from our eminent Perpetual Sscre tary of the Acadamy of Sciences, M. DvI mas, who is at the same time our President, which arrived this morning, via Auckland and Wellington. These Jast observa tions have bean made in a country in the midst of a nation young, but in x-eality old. She has understood that above material interests lie moral and scientific interests, which know neither rivalism nor war, but only emulation ani devotion. I must bear testimony to the fact that Otago has shown that she can do nrach for science. The Museum, and the geodesical operations of your President, Mr Thomson, are remarkable. Jn conclusion, Mr president and gentlemen, I beg you to accept my good wishes, and permit me to propose prosperity to the Institute. Lieut. Bass said he had the honour of proposing a toast, and he only regretted he was not able to make appropriate 1 emarks upon it, It wag only last May, or the latter part of April, that the American party first heard of the Otago Institute. They were then making preparations to come to the southern part of this island, and their first knowledge of the existence of the Otago Institute came to the ear of their department in the shape of some information in regard to the climate of the place, the peculiarities of the climate of certain districts, and certain localities were pointed | out to them in the interior of the Province where they would be most likely to get a clear and dist'net view of the sun on the 9lh December. Of course that was just the place they were looking for. At that time they'could not tell whether it would do to go into the interior of the country or not. Of course there were difficulties in the way of transporting apparatus, &c., and they could not form an opjnion on that point. Besides, they had read ovpr and over again of the dreadful Indian v/ars in thg country, and they had groat fear of being eaten up! Besides, in their ignorance they did not know what the Otago Institute was.— (Loud laughter and applause.) They were not at all certain but the Institu' were a set of cannibals that wished toiiv »them into the interior of the cour irdir just tq try hoy/- the Americar tletnen would taste. Hp did xiot ]vp,o\7 that they were altogether wrong in that suspicion after all, because they had been obliged to taste a great many public dinners since they had been here. They certainly felt very much indebted to the Institute, whic|+ had rendered every possible assistance, and had enable;! them to select a suitable station for observing"the tvansifc. A3 the assembly had been told by Professor Peters, the American party had succeeded in ob taining the greatest number of observations, if not the most valuable, of any taken at any one station in the southern hemisphere. That was certainly tho only example necessary to chpw thg advantage of such an institution as they had established here. ]j; was not necessary now at this period of ciyi'iisation to give any explanation as to the benefit of such institutions. They existed now in all civilised conntrit s Like the stroams that flowed down in all directions into the mighty ocean, the3e were the institutions through which knowledge floated down to the great mass of msnkjnd, conveying to them ideas of the adyaue'e of science and (jiyilibation. IJe had only to thank the Institute for tjjo assjat&nee rendered to the American Transit Party, and thgy ft-Jt pertain that h,icl it not been for the advice and assistance of the Institute they should have gone back empty handed instead of with the valuable results they had obtained, and which had been rendered much more valuable hy £he failure of some of their neighbours. He had, therefore^ to give thanks for the help rendered to the party, jpd for $he kind majiner in which "they Jj'ad been 'entertained ttyat nigljt. Th.ey should ever remember aud feel proud of having feeen the guests of the Institute. They trusted t}ie Institute would bp always successful in its objects and undertakinas fop the advancement o f knowledge. He therefore proposed ff The health of the Otago Institute."—(Applause.) His Honour Mr Justice Chapman said he had been requested to return thanks on bo half of the Otago Institute, for the cordial manner in which they had received the last toast. On this occasion they must not expect a long speech from him, as he was given £0 understand that there were a number of yo -ng ipd b,eaut;f'il ladies anxiously awaiting thja presence of pbej.r gallant French and American friends. ' Therefore, it" they granted f;o hsar a Ipng speech from Kirn they knew wher-e to go for ip. 4- wordg, however, were necessary in reply to {jhe haudsojije manner in which his American cousin, Lie lit. Bass, had spoken of the Institute. He was very glad tho Institute had been found at all useful. The existence of the Institute was of very short duration, being only four or five years old, and he hoped that if I/cut. Bass lived till the transit of Venus in the 36th pentary. and if lie should come fyere,'that'tye woujd find the Institute in a better condition to'scceiye him.' Tngy heatd a gfjod 4ea,l the repnblip of lexers, but he though^ t)}3 j;epu)jlio of science was a much moro real entity. The literature of one European country differed from the literature of every other JJuropoan country. Each had its specialty. The literature of France, admirable as it was, differed from the literature of England, which perhaps was equally a'linirable, and these in turn differed from the literature of Germany or of Italy. The literature of America, perhaps, appioached nearer to that of England tijiai} that of "any other country,' although perhaps \\i a less degree of late years, owing to its intimate intercourse with France and Gervnany. Science, however, was the same e'vevywhepe. — (fi'gar, JiOfTt) The truths of science were the game every, where; and if the science of one country differed from the science of another both of them could not be true. Therefore it were tljat he sgid there was a republic qf spience far morp jreally iman a republic of letters'; and he was happy to' say thatin a very humble way the' Otago Institute, or rather the New Zealand Institute, gf which the Otaqo Institute was a brancp, py thg exchange of itg Transactions, printed every'year, with a great numberof scientific societies in -Europe and America, was gping fa.ir to encourage that republic of gcience, which he hoped would never be extinguished. In conclusion, in the name of the President, himself, and the other members of the Otago Institute, he returned most cordial thanks for the manner in which the toast had been received.

Capt. Jacquemart then addressed the QQmpany ag follows ; J regret my inability

to speak English. My knowledge of English is too limited to admit of my addressing you in that language. We will speak no more of Venus. That is not my business. — (Laughter.) But as we leave this place to-morrow, 1 desire to return my heartfelt thanks for the aid my countrymen have, received. To the Government of New Zealand, the Provincial Government of- Otago, and the people—especially the citizens of Dunedin— we owe much. I thank you for your good fellowship, and shall bear it in mind wherever I may be on the globe. I have visited mauy parts of the globe, but in no place have I found myself more at home than in Dunedin. lam a sailor, and I give you thanks, sailor-fashion, for your reception of my countrymen and myself. The guests of the evening then retired. Mr li. Gillies, in a short speech, proposed "The University of Otago," coupled with the name of Professor Macgregor. Professor Macgregor replied in a humorous speech, and returned thanks on behalf of | himself and his colleagues, for the cordial, manner in which the toast had been received. | The meeting then broke up. .;