June 3, 1897] 



NATURE 



115 



which the year is divided in India, whereas from March 1895 

 to March 1896 it was more or less in defect in each season, 

 as is shown by the data of the following table. 



The variations in this table are calculated from the data of 

 over 2000 stations for which normal monthly means have been 

 calculated, and no allowance is made for the area represented 

 by each station. The total annual variation hence varies 

 considerably according to the two methods of calculation, but it 

 will be seen that they agree in the general character of the 

 cyclical variation : — 



The main features of the rainfall during this period were 

 hence not special to the south-west monsoon, but general and 

 affecting the meteorology of the whole year. This fact indicates 

 that the causes of the periodic variations are not only general, 

 but due to more or less permanent and persistent meteorological 

 conditions or actions affecting the meteorology of the whole 

 period over a considerable portion of the earth's surface. 



It has apparently been established in the discussion that the 

 variations of the rainfall in India during the past six years are 

 parallel with and in part, at least, due to variations in the 

 gradients, and the strength of the winds in the south-east trade 

 regions of the Indian Ocean. The discussion has indicated that 

 there are variations from year to year in the strength of the 

 atmospheric circulation obtaining over the large area of 

 Southern Asia and the Indian Ocean, and that these variations 

 are an important and large factor in determining the periodic 

 variations in the rainfall of the whole area dependent on that 

 circulation, and more especially in India. It has also been in- 

 dicated that these variations which accompany, and are probably 

 the result in part of abnormal temperature (and hence piessure), 

 conditions in the Indian Ocean and Indian monsoon area may 

 be in part due to conditions in the Antarctic Ocean, which 

 also determine the comparative prevalence or absence of icebergs 

 in the northern portions of the Antarctic Ocean. 



The economic effects of these very large variations of rainfall 

 during the past five years has been very great, almost disastrous, 

 in India. The variations are so large in amount, and affect so 

 vast an area, as to suggest that meteorological science should 

 have no difficulty in assigning the causes or chain of actions 

 leading up to these effects. Facts have been given in the 

 jiresent paper which suggest an explanation, but it is doubtful 

 whether it can be regarded as satisfactory. 



There appear to l)e only two explanations possible of this 

 periodicity. The first is that it represents large cumulative 

 effects of opposite phases in different parts of the earth. So far 

 as the whole Indian monsoon area is concerned, the variations in 

 different parts have not been compensatory ; and the rainfall in 

 1896 has almost certainly been below the normal, on the mean 

 of the whole area. It would be an interesting study for a 

 Central International Weather Bureau to investigate. So far 

 as can be judged from a brief examination of the weather reports 

 of other countries, there appear to have been no large and 



NO. 1440, VOL. 56] 



marked periodic variation in other parts of the world corre- 

 sponding to the variation in India — of either the same or 

 opposite phase. It is hence, on the whole, probable that the 

 periodic rainfall variation of the past five years in India has not 

 been compensated by a similar variation of opposite phases 

 elsewhere. If it were the case, it would be purely a question of 

 meteorological investigation. 



The second explanation is that this periodic variation of rain- 

 fall in the Indian Ocean during the past five years may be one 

 phase of general actions in the earth's atmosphere, due to 

 abnormal variations in the radiation and absorption of solar 

 energy, and hence to some abnormal phase of the sunspot 

 periodicity. Perhaps the observations recorded at Solar Physics 

 Observatories during the past five years may throw light on the 

 question ; and if such be the result, it would furnish a powerful 

 argument for India assisting in the work of Solar Observatories 

 to a much larger extent than she has hitherto done. 



The question which now affects India most seriously is, 

 whether the rainfall of the present monsoon is likely to be 

 seriously in defect. 



An examination of the figures certainly indicates a probability 

 that the mean rainfall of the year will be below the normal. If 

 the causes of the variations were known with certainty, it would 

 probably decide the question. J. E. 



THE INSTITUTION OF CIVIL ENGINEERS. 



C\^ Tuesday, Wednesday, and Thursday of last week, May 

 25, 26, and 27, the Institution of Civil Engineers held a 

 conference. This is a thing unprecedented in the annals of the 

 Institution, it having confined itself hitherto to weekly meet- 

 ings during the London season. Not only were there daily 

 sittings, many of them proceeding simultaneously, for the read- 

 ing and discussion of several papers, but there were also excur- 

 sions to works and "other objects of interest." There was, as 

 well, a conversazione ; but this is no novelty for the Institution. 

 A very large number of members attended the meetings, the 

 Westminster Town Hall and the Westminster Guildhall having 

 been retained for the purpose. The general plan of the con- 

 ference was for one or more members to read a short note by 

 way of initiating a discussion. As there were nearly fifty items 

 in the programme, the congress being divided up into seven 

 sections, it will be evident that in the small space at our disposal 

 we cannot even refer to all the subjects brought forward. 



Proceedings commenced at half-past ten on Tuesday, May 25, 

 by the President reading a short address in the Westminster 

 Town Hall, in which the scope of the conference was sketched 

 out. The members then dispersed to the different sections. 

 Section I. was devoted to railways, and the proceedings com- 

 menced by ISIr. Harold Copperthwaite reading a note on rails 

 and permanent way. He was followed by Mr. F. W. Webb, 

 of Crewe, who read a note on the same subject. The discussion 

 was of an entirely practical and professional nature. Mr. Webb 

 introduced a model of a joint chair ; that is to say, a device 

 which combined in itself a rail chair and fishplate. It will be a 

 great boon to railway travellers if this apparatus can be intro- 

 duced, supposing it will fulfil all the promises made on its 

 behalf by its originator, for there is no doubt that a very great 

 part of the jar and rattle of railway travelling is due to the 

 giving of rails at the joints. This fact was illustrated by means 

 of lead fishplates, which Mr. Webb had used for the purpose of 

 showing what was the amount of deflection at rail connections ; 

 it was considerable. The joint chair referred to is of massive 

 construction, and care will have to be taken that too much pro- 

 gress is not made in the direction of rigidity, otherwise there 

 will be repeated the old trouble experienced with stone blocks 

 for sleepers ; some flexibility is needful for a good road. In 



