THE TRANSIT OF VENUS.

New Zealand Times, Volume XXIX, Issue 4233, 14 October 1874, Page 2

THE TRANSIT OF VENUS.

A dinner was given a few days ao*o, at Christchurch, to the members of the English expedition to observe the transit of Venus. Dr. Haast presided. In proposing the toast of the evening the_chairman made the following observations : I think it is a most favorable omen that the day we have chosen for the celebration of the arrival amongst us of the three astronomers selected by Sir George Airey, the Astronomer Royal, for the observation of the ti’ansit of Venus, is the anniversary of the date on which, 105 years ago, another astronomer, who since then has gained a well-deserved world-wide fame, landed on the coasts of New Zealand. It was on the Bth of October, 1769, that Captain Cook on his Otaheite voyage, where he was sent by the English Government for the observation of the transit of the same planet, as it were, re-discoveied. New Zealand. And thus a voyage undertaken for one special purpose was fraught with the most important results in many other respects. This fact alone shows the influence of science in pi*omoting the civilisation of mankind and material progress of the world. 'Without that voyage, undertaken in the interests of pure science, this portion of ‘the Southern hemisphere would, in all probability, not have been as it now is, an important portion of the British Empire, with so many of the comforts and enjoyments of European life, and the high aims and aspirations of a steadily advancing community. It would be presumptuous in me to say much of our guests, personally and individually, in their immediate, presence, but their names are already well known to us. Major Palmer has achieved a good reputation in the various parts of the world in which he has served his Queen and his country, and lias never for a moment forgotten the claims that science lias upon him. The sound work done by him in connection with the great Sinaitic expedition lias brought his name into prominent and favorable notice throughout the scientific world. Lieutenant Darwin bears a name, and I may say, carries with him the personal features of one, whose position in the ranks of science is not only foremost in this century, hut will occupy in the future the same position amongst the investigators of biological science as is occupied by Newton in physical science. In one word, I am certain that he will prove himself the worthy son of an illustrious father. Lieutenant Crawford, on the other hand, differs from his two friends, in that lie is no stranger amongst ns, having already paid us a visit in H.M.S. Challenger. He has also had considerable colonial experience elsewhere, and I may be allowed to say that throughout the Australian colonies ho is recognised and spoken of as an ornament to his profession. (Applause.) Major Palmer replied. He remarked : “Venus men ” though we are* I must confes:. that not until now have we fully realised what the sensations of a “ star of the evening” must be. It certainly is' a very great privilege to be permitted, as we have been, to take part in what is perhaps the greatest astronomical enterprise which the world lias ever seen ; an ' enterprise which has for its object the determiua-" tion of the earth’s true distance from the sun—the “standard yard,” as it has been well termed, of dimensional astronomy ; for it is on this that we chiefly rely on for our measure of all the dimensions of the solar system, and of the distances of those few of the fixed stars whose remoteness can be guaged at all by any means yet known to science. But if anything could heighten the. pleasure and pride with which we serve in such an interesting undertaking, it would be the good fortune . which has brought us to this beautiful island as our sphere of duty, and the kind reception which we have met with from its inhabitants. And lam glad to have tins opportunity of stating publicly, for my officers and myself, how keenly we appreciate, not only the official facilities and the useful information which has been afforded to us by the General Government, by His Honor the Superintendent, the members of the Executive, and various officers of Government and private individuals, but also the personal kindness and hospitality which we have received since our arrival in Canterbury, and the compliment you have paid us in inviting us to bo your guests this evening. I spoke just now of the high scientific value of observations of the transit of Venus. But they have a utilitarian value also, which must not be over-

looked. To Great Britain especially, as the chief of maritime nations, anything which tends to ensure safety in navigation, has a direct practical and commercial importance ; and this is exactly the result which successful observations of the transit of Venus will help to bring about. The sailor, who has to find his absolute longitude at sea, depends upon the place of the moon at any given instant as predicted in the tables of the Nautical Almanac ; and these predictions are founded on what is called the lunar theory—or that theory by which astronomers, taking into account alb the forces which they conceive to influence the moon’s motion, have framed, in order that they may be able to calculate yea; s beforehand where the moon will be in thp heavens at any given moment. But the lunar f theory in its jn-esent shape does not fulfil these expectations. It is constantly at fault, at;d the moon is seldom exactly where she ought to be, if I may so say ; or, at any rate, where ti e,, tables would place her. She is a constant * . source of worry and perplexity to astronomers. As Sir George Airey once feelingly remarked to me, “ We don't mind the stars, Major Palmer, and we can get on pretty well with the sun and planets, but the moon is the greatest plague of all.” Vow, the chief reason, there . can be but little doubt, of this extraordinary apparent misbehaviour on the part of the nv on is. that we do not accurately know the earth’s distance from the sun : so you see that the transit of Venus will afford the moans of perfecting the lunar theory, and thus of improving the science of navigation, and adding, to the safety of commerce, and not navigation only ; for it will aid in the determination of absolute longitude at all points of the earth’s surface which are not by telegraph with fixed observatories. You will probably like to hear something from me before I sit down about the doings and prospects of the New Zealand part of the enterprise. The site which I have chosen, as probably most of you are aware, is on the Government at Burnham, eighteen miles away. I did not make my decision -without a good deal of inquiry and anxious consideration. The difficulty of-selection was much greater than anyone unacquainted with this neighborhood would be likely to expect. The ordinary requisites for a site for an astronomical observatory arc simple and obvious enough. But, in this particular case, wo had to consider, first and foremost, where is the spot which is most likely to afford a good view of the sun on the afternoon of the 9th of December, and which is not unsuitable, in other respects, as an obsorvatmy site. And here I was faced with a number of subtle considerations, chiefly arising out of local peculiarities of climate and atmosphere, which it was a very troublesome matter to rift and digest. But I received, in the course ofmy inquiries, so much aid from various gentler.; on who had given attention to such matters, that I was able to see my way clearly to a decision in favor of Burnham, the site first suggo.-te.l t.. me by His Honor the Superintendent. And I am glad to hear, as I have since done, that there is a general concurrence of opinion on the po rt of those who, of course, know the district, much better than I can possibly know ic, that no more favorable spot could have been fixed upon. On Friday last we began operations on the ground, and I hope that early next week we shall have our transit instrument and clock erected and adjusted. The other three principal instruments—namely, the altazimuth, the equatorial telescope, and Mr. Darwin’s particular pet, the photoheliograph, will follow in a few days, so that I hope to be in full working order in about a fortnight hence. J ooking seaward, there will be, according to present arrangements, the Americans at Chatham Islands, the Germans at the Auckland Islands, and the French at Campbell Island ; and I am in hopes that, with the assistance of H.M. ships, we shall be able to undertake chronometric expeditions to those points for accurate determination of differences of longitude. You see, therefore, that by these means, full provision wiE have been made in this region for successful observation

of the transit of Venus ; the whole group of stations will have been connected together, so that direct comparisons may he made between the various observations ; and lastly, yon will have secured a fundamental longitude for New Zealand which, it can be no oifenco to say, is likely to exceed in accuracy your previous absolute determinations.