574 



NA TURE 



{Oct. 14, I ! 



cision. This condition is especially important in such \vorl< as 

 that of stellai parallax, the determination of the constant of 

 aberration, and wherever the yearly change of temperature may 

 act injuriously. In the selection of better sites for observatories 

 I think we have an easy means of advancing astronomy. 



As this science grows and expands, it will become more and 

 more necessary to study the economy of its work, in order that 

 astronomers may bestow their labonrs in the most advantageous 

 methods, and may rid themselves of all cumbersome and time' 

 consuming processes. The manner of publishing observations 

 has already been much abbreviated, and improved I think, by 

 some of the European astronomers, and this change seems 

 destined to become universal. As the positions of many objects 

 are now well known, the need of printing all the details of the 

 observation, such as the transits of the wires, the readings of the 

 micrometers, &c. , is very slight ; and this printing may be safely 

 abandoned. Even this change will lead to a great saving in the 

 time and cist of printing. But this will necessitate a more 

 complete discussion of the work, and a more careful examination 

 of the instruments ; things to be desired, since they tend to lift 

 the observer out of his routine, and make him a master of his 

 bxisiness. There are objections to this change, and some of 

 them are real, such as the importance of publishing a complete 

 record ; but this is overestimated, X think, since the original 

 records ought always to be referred to in case of doubt ; and 

 other objections are factitious, such as the need of publishing 

 a large and showy book in order to impose on the public. 



We may hope also for improvements in theoretical .astronomy, 

 and for the better training and preparation of students of this 

 science. I know that it is sometimes said that theoretical astro- 

 nomy is finished, and that nothing more can be done. Such 

 assertions come from professors who are old and weary, or from 

 those young men who tire out early in life ; but they are wrong. 

 The improvements that Hansen has made in the theory of 

 perturbations, and Poinsot's study of the theory of rotation, show 

 what careful investigation may do, and assure us of further pro- 

 gress. It must be confessed that some of the astronomical work 

 done in our country bears evidence that the astronomers did not 

 understand the correct methods of reduction, and much of it 

 shows evidence of hasty and ill-considered plans. This is per- 

 haps a natui-al condition for beginners, but we trust that it has 

 been outgrow, 1. An actual need for the astronomical students of 

 our country is a good book on theoretical astronomy, similar to 

 Pontecoulau'-'s work, in which the ^^hole subject shall be pre- 

 sented in a complete form, such as we find in the " Mecanique 

 Celeste," together with an account of the improvements made by 

 Gauss, Poisson, Hansen, and others. There is no American 

 book of this kind, and the English works are too partial, designed 

 apparently to fit the student for college examinations, and not to 

 give him a complete knowledge of the science. Such a book has 

 hardly been attempted in our language, unless that of Wood- 

 house may be an exception, and it may be a long time in coming, 

 since it requires a man qualified to do the work, and will involve 

 ail expense of labjur in the preparation and of cost in publishing 

 such as few are u illing to incur. In the mean time it is far 

 better fur tlie student to go directly to the writings of Lagrange 

 and Laplace, of Gauss and Poisson and other masters, rather 

 than to spend time in reading second-rate authors who endeavour 

 to explain them. And generally this will be found the easier 

 way also, since the student avoids the confused notions and 

 symbols, and the grotesque expressions and egotism of small 

 men, and is lifted into the region of ideas and invention. 



In presenting his exposition of the nebular hypothesis, which 

 has since become so celebrated, Laplace says: "I present this 

 hypothesis with the distrust which everything ought to inspire 

 that is not a result of observation or of calculation." It is a 

 singular fact that, among all the writings on the nebular hypo- 

 thesis, I have never seen a reference to this presentation of it by 

 its most distinguished advocate ; and yet this is the true spirit 

 of scientific astronomy. Laplace did not wish to exempt his 

 own theories fr.im criticism, and neither should any one. In 

 astronomy there is no final human authority, no synod or council, 

 but siiiiplv an appeal to reason and observation. If a theory or 

 a discovery be true, it will stand the test of observation and of 

 calculation ; if false, it must pass away to that Miltonian limbo 

 where so many things have gone and are going. The question 

 is sometimes asked. Of what use is astronomy ? and the reply 

 generally made is that it has conferred great benefits on naviga- 

 tion and on commerce, since it is by means of his as'ronomical 

 knowledge that the sailor determines the position of his ship on 



the ocean. There is a truth in this reply, but it is only partial. 

 The great value of astronomy is that it is really a science and 

 that It has broken the path and led the way through which all 

 branches of science must pass if they ever become scientific. It 

 is the spirit of honest, unrelenting criticism, and of impartial 

 examination, that finally eliminates error and awards to every 

 one his just due, that makes astronomy honourable and attractive ; 

 and It is by cultivating this spirit that astronomy confers its chief 

 benefit, for it is this that shall break in pieces and destroy all 

 false assumptions in science and in philosophy. 



SCIENCE IN NORWA V 



\\/'E have received several publications from Norway of 

 scientific interest. 



Nyt Magazin fur Naturvidenskabernc. B. 25, II. 4. 

 (Kristiania, iSSo.) 

 ^lu this number of the Norwegian "New Magazine for 

 Natural Sciences" Herr Hansen continues his description ol 

 the annelids yielded by the Norwegian North Sea Expedition 

 of 1878, to which he appends drawings of his own of all the 

 rarer forms. — Herr L. Schmelck gives the results of his analysis 

 of sea-water obtained in the same voyage within and near the 

 Polar circle. The water was taken at various depths, and was 

 obtained from a stratum intermediate between the surface and 

 the bottom by means of an apparatus devised for the purpose by 

 Herr Tornbe. — Herr Brbgger and Reusch's observations on the 

 character and localities of Norwegian apati'e, which originally 

 appeared in 1875 i" tl^e Zeitschrift d. dmtschen geclogischen 

 Gesellschaft, are here translated into Norwegian by the authors, 

 who have made various additions to their paper, which is 

 illustrated with numerous drawings. — In a paper on the Lepi- 

 doptera of Norway by W. M. Schoyen the author draws 

 attention to the number of new forms added to this branch of 

 the NoruC'/ian fauna smce the publication, in 1876, of Siebke's 

 list of the insects of Norway. The number given at that time 

 for the lepidoptera was 934 ; it is now raised to 1,019. The 

 writer's own contribution to these is 38 hitherto undetected 

 Norwegian species, the habitats and characters of which lie 

 describes. 



Kort Fremstilliiig af de Norske Kiirstedeis Udviiting, c&^r. 

 Ved Axel Lund, M.D. (Kristiania, iSSo.) — In this /'^ft/jHr^ we 

 are reminded that Norway, from her geognostic character, is 

 naturally deficient in thermic spiings, and we are shown that till 

 recently the waler-cure — taking the words in a comprehensive 

 sense to include the use of waters internally and externally — was 

 unknown in the country. In fact even now the Norwegians 

 stand exceptionally low in the scale of water-using nations, al- 

 th.jugh an encouraging change in this respect has been manifested 

 of late years by the establishment of mineral and sea-bathing 

 places in various parts of the kingdom. These Dr. Lund de- 

 scribes at great length, giving the analysis of the waters yielded 

 by the few springs that have been opened, and the amount of 

 salt present in the sea-water at the various marine stations, with 

 the medical reports of each and the mode of treatment adopted. 

 In the last respect the only difference that we observe from the 

 system generally followed at German baths is that at the sea- 

 bathing establishment in the Sandefjord, a small species of 

 Medusa is used to excite local irritation in cases of cerebro- 

 spinal, rheumatic, or neuralgic affections, by passing the animals 

 rapidly over the p"rts affected. To Dr. Thaulow, the founder 

 of the baths at the Sandefjord and at Modum, the Norwegians 

 owe a large debt of gratitude as the first of their countrymen 

 who drew public attention to the paramount importance of batlis 

 as a hygienic agent. .Sweden has long been in advance of Nor- 

 way in its appreciative comprehension of the curative value of 

 mineral and sea-waters ; and from Dr. Lund the reader will 

 learn all that there is to learn in regard to the water-establish- 

 ments, springs, and baths of the sister kingdom, while he may 

 also gather some information respecting similar institutions iu 

 the Danish dominions. In conclusion, we may observe .that 

 some of the uewdy-opened Norw-eglan water-cure establishments, 

 as that of Modum, lying in the midst of pine-woods, and the 

 sea-bathing places on the Sandefjord and Kristianiafjord, offer 

 numerous attractions to foreigners in respect to salubrity of air, 

 beauty of position, and moderate cost of living. 



Knudshoydkr Fjeldfloraen. J. B. Barth. (Kristiania, 1880.) 

 — Herr Barth, who is v\ell known for his animated descriptions 

 of the natural scenery of his country, and his lively narrative of 



