Mat 1, 1898.] 



KNOWLEDGE. 



98 



In future The Observatory will be conducted by Mr. 

 T. Lewis and Mr. H. P. Hollis, both of the Royal Observa- 

 tory, Greenwich. Mr. H. H. Turner remarks, in an 

 editorial notice, that Dr. Common and himself have 

 withdrawn from the editorship because the many calls 

 upon their time prevent their giving the attention to the 

 magazine which alone could ensure its being a complete 

 record of current astronomical events. 



Lord Rayleigh, in lecturing at the Royal Institution on 

 interference bands, exhibited as an illustration of wave 

 action a " bird-call," whose pitch was so high as to be 

 inaudible. The concentration of the air waves, however, 

 on to a sensitive Hame, by means of a screen, caused the 

 flame to roar in a remarkable manner. 



It is commonly known that the simple relation between 

 planetary distances, termed Bode's law, was first dis- 

 covered by J. D. Titius, of Wittenburg. Mr. W. T. Lynn 

 points out in The ohserrntory that Titius seems to have 

 suggested that the gap between the orbits of Mars and 

 Jupiter would be filled by the discovery of new satellites. 

 Bode, on the other hand, expressed the view that the gap 

 pointed to the existence of a new planet, and when Ceres 

 was discovered in ISOl he claimed the fulfilment of his 

 conjecture. This probably explains why the geometrical 

 progression of planetary distances is known as the law of 

 Bode instead of the law of Titius. 



Some experiments on the resistance of ice have recently 

 been made in France. From the results it appears that a 

 thickness of rather more than one and a half inches is re- 

 quired to bear the weight of a man on the march ; a thick- 

 ness of three and a half inches is sufficient to permit the safe 

 transit of detachments of infantry in files ; and with about 

 four and three-quarter inches, guns may be transported across 

 the ice. M. Forel points out in the Eeviie Si-ientiti(jue that 

 these estimates apply only to young ice. Ice which has 

 been exposed to alternations of temperature for a few weeks 

 loses much of its tenacity and breaks far more readily than 



younger formations. 



— .-♦-< — 



At the Royal Society, on March 23rd, Lord Rayleigh 



communicated a paper on " The Densities of the Principal 



Gases." He has determined the absolute densities of 



air, oxygen, and nitrogen, by comparing the weight of a 



volume of each of these gases with that of an equal 



bulk of water. The results obtained, reduced to standard 



conditions, are : Air, 000129327 ; oxygen, 0-00142952 ; 



nitrogen, 0-00125718. Taking the ratio of the densities 



of oxygen and hydrogen as 1.5-882, the absolute density of 



the latter gas is found to be 000009009. If the density 



of air is taken as unity, the density of oxygen is found to 



be 1-10535, of nitrogen 0-97209, and of hydi-ogen 



006960. 



The following are among the lecture arrangements at 

 the Royal Institution after Easter : Mr. John MacdoneU, 

 three lectures on symbolism in ceremonies, customs, and 

 art ; Prof. Dewar, five lectures on the atmosphere ; Dr. R. 

 Bowdler Sharpe, four lectures on the geographical distri- 

 bution of birds ; Mr. James Swinburne, three lectures on 

 some applications of electricity to chemistry (the TyiidaU 

 lectures). The Friday evening meetings were resumed on 

 April 14, when a discourse was given by Sir William H. 

 Flower, on seals. Succeeding discourses will probably be 

 given by Prof. A. B. W. Kennedy, Prof. Francis Gotch, 

 Mr. Shelford Bidwell, the Right Hon. Lord Kelvin, Mr. 

 Alfred Austin, Mr. Beerbohm Tree, Prof. Osborne Rey- 

 nolds, Prof. T, E. Thorpe, and others. 



The reported discovery of Prof. Emmerich, that the 

 blood of an animal which has recovered from an infectious 

 disease can cure another animal suffering from the same 

 disease, seems likely to prove of considerable importance. At 

 the last meeting of the Berlin Physiological Society some 

 remarkable statements regarding the facts arrived at were 

 made. ^lice had been inoculated by the serum or watery 

 portion of a horse's blood, the horse having been already 

 cured of the disease ; the result was that the mice, which 

 had been previously inoculated with the bacilli of lock-jaw, 

 did not die when subjected to the treatment, while those 

 left to themselves perished. Experiments are to be tried 

 on human beings. 



In a recent lecture at the Royal Listitution, Dr. E. 

 Hopkinson remarked that the engineer only begins to 

 realize the imperfections of all his works when he contem- 

 plates the amount of energy involved in his final purpose 

 compared with the energy of the coal with which he starts. 

 Beginning with the energy in a pound of coal, and tracing 

 its loss step by step, it appears that in the case of the most 

 economical electric railway, the energy expended on the 

 passenger is but little more than one per cent, of the energy 

 produced by the burning of the coal. Even this result is 

 better than lighting with incandescent lamps, in which only 

 about one-half per cent, of the original source of energy is 

 utilized. When we consider that, both in transportation and 

 lighting, more than ninety-nine parts in a hundred are now 

 wasted, it will be seen that the future has great possi- 

 bilities. 



— *-♦-< — 



Prof. Bonney, F.R.S., in his paper read before the 

 Royal Geographical Society on "Do Glaciers excavate '? " 

 made a vigorous attack on the theories of Sir A. Ramsay's 

 school, which attribute to glacial action the great lakes or 

 rock-basins of Switzerland and elsewhere, sometimes more 

 than 1000 feet deep. His investigations as to the action 

 of moving glaciers from 1860 to 1890 seem to show that 

 they do little more than modify existing features of the 

 land, rounding off prominences, scraping up gravel, and so 

 on. Prof. Bonney's theory of the origin of rook-basing, 

 which he brought forward twenty years ago, is that lake 

 beds are ordinary valleys of sub-aerial erosion, affected by 

 differential earth -movements. In support of this view he 

 quotes many different surveys ; that of the great lakes of 

 America serving especially to confirm it. The beach of 

 the Iroquois, for instance, is 600 feet higher at the north- 

 east part than it is at the western end of Lake Ontario. 



At a meeting of the Royal Geographical Society on 

 Monday, March 13th, Mr. H. 0. Forbes, a well-known 

 naturalist, discussed in an illustrated lecture the question 

 of the former extension of an Antartic continent in relation 

 to certain observations made during a recent visit to the 

 Chatham Islands. He found there the remains of a large 

 and remarkable bird, a member of the rail family, viz., the 

 aphanapteryx, which lived contemporaneously with the 

 celebrated dodo in the island of Mauritius, and was very 

 similar to one of the extinct flightless birds of that island. 

 In the Chatham Islands there still live several types of 

 flightless birds scarcely represented elsewhere, except in 

 widely separated oceanic islands ; and to account for their 

 distribution it is necessary to assume very different 

 geographical conditions from the present. An animated 

 discussion followed. Dr. Slater was against a former 

 Antartic continent ; Dr. Henry Woodward, Dr. Gunter, 

 and others, spoke in its favour ; and the soundings of the 

 Southern Ocean, so far, confirm the view advocated by 

 Messrs. Forbes, Wallace, Blandford, and others. 



