542 



NATURE 



[Sept, 19, 1878 



crater cones upon the floor of the walled plain Plato, 

 which were very variable in visibility; also of sevei"al 

 streaks which were not only variable in visibility but also 

 in form ; the most usual shape that was observed was 

 that of a trident on the south-west part of the floor. 

 There appeared to be a close connection between the 

 spots and streaks, but its nature was not mentioned in 

 the reports further than a surmise that the appearance 

 of certain streaks appeared to be coincident with an 

 increased visibility of certain spots. Another result was 

 a brightening of the north-west floor, for a time only, as 

 Avell as a brightening of several of the streaks, but per- 

 haps the most important was that of a darkening of the 

 darker parts of the floor as the sun rose higher above its 

 horizon. This result has been most strenuously contro- 

 verted by a popular writer, who alleges that the effect 

 observed was due only to contrast. Be this as it may, 

 the Report for 1872 is explicit as to a gradual darkening 

 with increased solar altitude; at any rate the same writer 

 bears testimony to the exceptional care with which the 

 floor was scrutinised. 



In the year 1876 (May) Nelson's " Moon and the Con- 

 dition and Configuration of its Surface," appeared. It 

 marked an era in selenographical research, the English 

 student having within his reach, for the first time, a 

 description of the principal formations on the moon's 

 surface in his own language. This work, of 576 pages, 

 includes a map drawn in twenty-two sections, the prin- 

 cipal formations on each being fully described in the 

 body of the work. Besides the purely topographical part, 

 the author has given five introductory chapters in which 

 he has treated of the physical condition of the surface, 

 the general characteristics of the lunar formations and 

 the variations that have from time to time been detected 

 on the surface. He has also given a most lucid chapter 

 on the history both of the progress of mathematical in- 

 vestigation and selenographical research as regards the 

 moon. 



The most important re:ent event in the progress of 

 selenography was the discovery, on May 19, 1877, by Dr. 

 Klein, of a dark spot which he described as " a great 

 black crater full of shadow without a wall north-west 

 of Hyginus," (NATURE, vol. xviii. p, 197). It was 

 first announced by him in his Wochefischrifi fur As- 

 tronomic for March, 27, 1878, and has since been seen 

 by several observers who have generally confirmed the 

 appearances mentioned by him, and also agree in their 

 testimony that no such spot existed formerly in the 

 region in which it was seen. In the celebrated case 

 of Linn^ the information in 1866-67, as regards the/(?r;;/r/- 

 condition of the surface of the moon was so imperfect 

 that it was considered by astronomers that "no change 

 in Linnd could hare taken place, but that Lohrmann, Beer 

 and Madler, and Schmidt must have been mistaken." ' A 

 considerable controversy on this subject occurred during 

 1867-68, but nearly six months have elapsed since Dr. 

 Klein's announcement, and we hare not heard of his dis- 

 covery having been seriously questioned. It is true that 

 a certain white spot, alleged to have been found on pho- 

 tograms taken within the last fourteen years, has been 

 regarded as indicative of the existence of Klein's crater 

 during those years, and from the probability of its locality 

 being that of Klein' s crater, the conclusion has been drawn 

 that the latter is not new. Admitting that a somewhat 

 similar spot existed thirteen years ago, the real nature of 

 which we are unacquainted with, and which may have dis- 

 appeared in the interim, we are quite as much in the dark 

 as to the real nature of the change ascertained to have 

 taken place by Klein, as to the former existence of the 

 spot discovered by him ; both await further elucidation. 



The recent publication of Schmidt's large map of the 

 moon in twenty-five sections indicates the latest era of 



' Nelson. "The Moon, and the Cond'.t'.on ani Configuration of its Sur- 

 face, p. 125. 



progress. If selenographers apply themselves ener- 

 getically to examine it, the study of the moon's surface 

 will make great progress ; but for this purpose much self- 

 denying labour is indispensable, as the map contains as 

 many as 32,856 craters, exceeding those recorded by 

 Madler by 25,121. It is important for the true progress 

 of selenography that all of these newly-recorded craters 

 should be observed in such a manner as to leave no doubt 

 of their existence. To effect this each observer should 

 keep his record of observations in the form of a catalogue. 

 In the earlier part of this article we have alluded to the 

 plan adopted by the British Association, viz., of cata- 

 loguing every object inserted or to be inserted on its map, 

 and we have also alluded to those publications which 

 contain the descriptions of 710 objects. We believe that 

 a comparison of those publications with Schmidt's map is 

 in progress, and that some of the objects in them are not 

 in Schmidt's map. It is, therefore, certain that, inde- 

 fatigable as Schmidt has been, if we regard his map as 

 perfect we shall make a great mistake. May w^e rather 

 endeavour to add to the already large number of objects 

 which he has chronicled. 



H YDRO-INCUBA TION ^ 



WE wish that Mr. Christy had used a less barbarous 

 term for his useful apparatus : that, however, is 

 of little consequence to practical men. 



At a time when our native farm-yard and dairy pro- 

 duce only supplies about two-thirds of what London and 

 our secondary and third-rate towns need, anything that 

 will assist the unready Saxon in so unsatisfactory a state 

 of things ought to be received with gratitude. 



Fowls, in a dietetic point of view, are, we are satisfied, 

 certainly of much more importance than is ordinarily 

 supposed. Let any thoughtful medical man in general 

 practice think what a comfort it would be to him if well- 

 fed young fowls were available for the poorer among his 

 patients, and he will agree with us that such an apparatus 

 as Mr. Christy's may become a great boon. That the 

 masses of the people should be able, in time of illness, 

 to purchase useful wine, the more delicate kinds of fish 

 (such as whiting and soles), fresh eggs, and succulent and 

 tender poultry — these are things desirable to a degree 

 only known to those who are familiar with the treat- 

 ment of diseases in the homes of the common people. 

 Many a kindly Family Doctor passes from house to 

 house heavy-hearted as well as (too often) overworked ; 

 the sad answer to his advice as to regimen being, again 

 and again — " It is easy. Sir, for you to prescribe, but how 

 can we afford these luxuries." 



The old remark as to the value of an improvement in 

 the grazing department of the farm, that should " make 

 two blades of grass grow where only one grew before,' ' is 

 now more than ever pertinent. Let our readers look at 

 the Registrar-General's returns for London only, espe- 

 cially in a very healthy season, such as last year, and he 

 will see that the number of the births weekly, as compared 

 to the deaths, is such as to add about two thousand 

 hungry mouths to the population in three weeks. Then 

 from all the provinces men and women are pouring into 

 London and the large towns, where they need in the 

 closer air more and better food than would have sufficed 

 them in the country. Therefore we are glad to see ener- 

 getic merchants. like Mr. Christy, bestirring themselves to 

 see what new cattle-food can be found from other climates, 

 and how our rural people can be stimulated and helped to 

 grow and develop for their own benefit and for the benefit 

 of others, food of many kinds that shall be as "manna" 

 to thousands and myriads of hungry people. 



But there is another, and much more limited, sphere in 

 which such an apparatus as the "hydro-incubator," will 



' " Hydro-Incubation in Theory and Practice." By Thomas Christy, 

 F.I..S. Second Edition. (L?ndon : 1878. 



