July 22, 1897] 



NATURE 



281 



mountainous regions correspond to the successive depressions of 

 the regions occupied by the seas. The obstruction of these 

 fissures by the overflowing of lava has given most of them the 

 aspect of prominent veins which can be seen branching at the 

 surface of the seas, or crossing the middle part of some great 

 walled plain. But amongst the concentric crevices at the seas, 

 those which have remained open must have been contemporary 

 with the most recent movements of the soil. 



"If, however, we try now to compare and to make these 

 two orders of parallel facts, often associated in the same region 

 of the moon, agree, we shall be brought back by a slightly 

 different way to the same chronology which we have already 

 shown to be the most probable. 



" The rectilinear furrows, transformed into elevations by 

 a strong lateral pressure, or, on the contrary, into large valleys 

 by a gradual disjunction, belong all to the first period — that 

 in which the crust possessed a certain degree of mobility in the 

 horizontal direction. 



" The second period pertains to the forces of elevation which 

 acted on extended areas, irregular as regards their boundaries. 

 At this period great mountains begin to be formed. There are 

 few forms sufficiently characterised which can be traced back to 

 this obscure epoch of transition. 



" Nevertheless the elevated regions with a scarcity of walled 

 plains, covered with scorire which has accumulated without any 

 regularity, can give an idea of what the general aspect of our 

 satellite must have been at that time. The group of the Apen- 

 nines is undoubtedly the most important vestige which remains 

 from that epoch. In a third period appear conical intumescences, 

 the first outlines of the walled plains. These obtain their real 

 actual physiognomy by the progressive depression and the 

 partial submersion of their central region. 



"The fourth period, the grandest and most durable in its 

 effects, brings about the destruction of a great part of the 

 anterior relief, and gives to the whole of the lunar globe an 

 aspect differing very little from that which we see now. The 

 depressions, caused by the general contraction of interior fluid, 

 include at once the vast regions which we designate by the 

 name of seas, and cause immense quantities of lava to flow back 

 in uniform sheets to the surface. The mountainous plateaus 

 appear as isolated groups, and in the intermediate spaces a 

 mass of furrows and walled plains disappear by submersion. 

 An idea of the importance of the change brought about, will 

 be gathered by comparing the polar and equatorial regions, so 

 unlike to-day, but which, without doubt, formerly bore the 

 same aspect. 



" The first new features which become visible in the uniform 

 plains thus formed are crevices which follow their borders and 

 increase with the progress of the depression, until a fresh over- 

 flowing of lava takes place, stops them up, or transforms them 

 into prominent lines. The most recent cracks can remain open, 

 or become visible by the difference of altitude which exists 

 between the two edges. This fourth period brings the lunar 

 crust to a more .stable condition, of which it did not actually 

 appear possible to foresee the end. The local eruptions always 

 become visible across the crust already solidified, and complete 

 the fifth period. In the mountainous parts they create para- 

 sitic orifices, which degrade and render unrecognisable the 

 ancient formation*. In the seas the volcanic forces, which are 

 obliged to cross a thicker and more homogeneous crust, enforce 

 the appearance of rei;ular cones, generally transformed into 

 little walled plains by the depression of their centre. Some 

 large formations, such as Copernicus, have probably appeared 

 in this way. Most of the walled plains thus created in relatively 

 recent times can be distinguished by their isolated situation in 

 the middle of a plain, by the regularity of their form, by the 

 white borders which surround them, and which indicate violent 

 eruptions experienced in the neighbourhood of their centre. 



•' These inductions can, naturally, only acquire a convincing 

 nature if the objects in question, or at least their exact image, 

 are before us. When Beer and Madler published their great 

 work on the moon in 1837, they limited themselves to simply 

 stating facts. They themselves acknowledged they had tried 

 to eliminate from their descriptions all that could lead to 

 a tendency to theorise, and favour any particular view con- 

 cerning the actual state of the moon and the history of its meta- 

 morphoses. It has seemed to us that the editor of a photographic 

 document was not bound to such reserve. The authenticity of 

 the facts on which he relies can be absolutely verified. Placed in 

 the presence of a true and impartial reproduction, the reader is 



NO. 1447, VOL. 56] 



in a position to judge for himself, and to have an independent 

 opinion. It is not wanting in any respect to him, but to 

 facilitate this task, that we try to formulate the very varied 

 problems which the examination of the moon suggests, to report 

 the most curious facts, and the examples which are best for 

 determining the choice between the different possible theories. 

 We have endeavoured to do this in the notice which accom- 

 panies the second part of the Atlas, of which the preceding 

 lines contain the principal ideas." 



THE INTERNA TIONAL CONGRESS OF NA VAL 



ARCHITECTS AND MARINE ENGINEERS. 

 ''PHE recent congress of Naval Architects and Marine En- 

 gineers, which was brought to a conclusion on Thursday 

 of last week, July 15, has taken the place of the usual summer 

 meeting of the Institution of Naval Architects. As our readers 

 are aware, the two preceding summer meetings of this Institu- 

 tion have been held respectively in France and Germany, and 

 on both occasions the meetings have been of more than usual 

 brilliancy and importance. The generous hospitality extended 

 to members of the Institution in Paris, Berlin, and Hamburg 

 created a very natural desire on the part of those entrusted with 

 the conduct of the affairs of the Institution to do something to 

 show that the sympathetic and friendly feelings aroused extended 

 beyond mere expressions of gratitude conveyed in speeches and 

 formal documents. It was determined therefore to hold a con- 

 gress in London this year, at which naval architects and marine 

 engineers of all nations should be the honoured guests of the 

 Institution. The Earl of Hopetoun, the President of the In- 

 stitution, threw himself into the work of forming a reception 

 committee with characteristic enthusiasm, and was most ably 

 seconded by Mr. George Holmes, the Secretary of the Institu- 

 tion, on whom, naturally, the chief burden of the work has 

 fallen. A subscription list was opened, and, being most liberally 

 supported by the leading members of the Institution, there 

 was no lack of the most needful feature for success in all opera- 

 tions of this nature. The result has been one of the most bril- 

 liant and successful gatherings yet held by a technical society. 

 Foreign delegates, representing the leading men in the twin 

 sciences of naval architecture and marine engineering, attended 

 in response to the invitation of the reception committee, and 

 the whole proceedings were so perfectly organised by Mr. 

 Holmes and his staff that the congress passed off without a break 

 in the continuity of success. 



In a grand function of this nature it is the social and inter- 

 national aspect which attracts attention rather than the scientific 

 bearing. When the Queen extends hospitality, when the heir to 

 the throne presides, even the most austere seeker after scientific 

 truth may, perhaps, relax, and lose sight for a time of 

 the sterner aspect of the meeting. Two sittings were held at 

 the Imperial Institute for the reading and discussion of 

 papers, but undoubtedly the chief features of the congress were 

 the reception of the members and foreign delegates by Her 

 Majesty at Windsor, the inspection of Portsmouth Dockyard, 

 and the subsequent cruise in the Solent on the mail steamer 

 Mexican, the conversazione held at the Mansion House by the 

 Lord Mayor and Lady Mayoress, the reception by the First 

 Lord of the Admiralty at his official residence, the Honourable 

 Mr. and Lady Idina Brassey's soiree at Lord Brassey's house in 

 Park Lane, and the concert at the Queen's Hall, in which the 

 magnificent Yorkshire choir played so prominent a part, and 

 at which Madame Albani was the principal singer. In addition 

 to this there was a more business-like visit to the Docks, an 

 opening reception on the first evening of the congress at the 

 Hotel Cecil, and the annual dinner of the Institution. It is, 

 however, not within our province to chronicle these delights ; 

 but before glancing at the more business part of the congress, 

 we may call attention to the excellent effect produced by 

 international gatherings of those devoted to applied science 

 drawing closer the ties of friendship. The leading ship- 

 builders and marine engineers are men of high position 

 and influence in the country. Their visits to France and 

 Germany have led to the most pleasant relationships, and 

 these have been cemented by the visit of so many foreign 

 delegates during the recent congress. These things make 

 for peace ; so that when a section of the daily press, at 

 home or abroad, is occupied in its frequent endeavour to stir 

 up ill-feeling between different peoples, it will find its un- 



