692 report — 1878. 



If for. large rivers, where navigation only, without drainage, had to be con- 

 sidered, the necessary weirs to obtain sufficient sailing depth were made movable 

 down to the bed even when locks were provided, as in France and India, with far 

 greater reason should they have been made movable down to the bed on the Shan- 

 non, where the drainage of the Callows and low riparian lands was a part of the 

 original design. 



5. The Rainfall of Ireland. By Gr. J. Symons, F.B.S. 



The author mentioned that the Irish hills do not appear to exhaust the rain- 

 clouds so much as the English hills do. With the exception of a dry central area 

 round Dublin, the rainfall all over Ireland may be taken to be almost the same. At 

 present, instead of the greatest rainfall being in the south-west, or in Galway, 

 we had the wettest spot of all (with one exception) under the shadow of Slieve 

 Donard, in the south of the county Down, the very place which, theoretically, 

 might be expected to be almost the driest part of Ireland. That showed that 

 it is really more a question of the elevation of hills than of geographical position. 

 He exhibited a map showing the number of stations established for the observa- 

 tion of the rainfall, and the averages at many stations. From 1866 to 1876 

 there were thirty stations established, at which the rainfall was regularly re- 

 corded, and at those stations the fall in the ten years was not very different from 

 that in the five years 1872-76. It was, therefore, a fair conclusion that the 

 average from 1872 to 1876 was not far wrong. It might probably be wrong 

 3 or 4 per cent. 



He had succeeded since the meeting of the Association in Belfast in obtaining 

 the services of a large number of gentlemen volunteers throughout Ireland, who 

 had taken charge of the rain gauges supplied to them, and had engaged to 

 register their observations. There were still large districts, however, in which he 

 had not been able to establish rain gauges, and the observations were, therefore, 

 necessarily defective as to the average rainfall. There was a large district in the 

 neighbourhood of Longford without a single station, and another in the south- 

 west of Cork, where it was essential that observations should be taken. If he 

 could induce some gentlemen having property in those neighbourhoods to take 

 charge of rain gauges, Ireland, instead of having to .depend upon ten stations, as 

 it did not many years ago, would be fairly repre3ented, both geographically and 

 physically. 



6. On the Hydrogeological Survey of England* By Joseph Lucas, F.G.S. 



The need of a National Hydrogeological Survey having been admitted at the 

 Congress on National Water Supply at the Society of Arts, the author passes on to 

 the consideration of how the information collected by the survey may be brought to 

 bear so as to produce the result aimed at, viz., the improvement of the water supply 

 of the country generally. 



The product of the survey is a map, on which the necessities as well as the capa- 

 bilities of each river basin are made to appear. The author proposes that on the 

 completion of the map of the first (and each subsequent) river basin the Government 

 should invite the competition of engineers to frame comprehensive schemes of a dis- 

 tributary character, based on the watershed area, and should appoint a special com- 

 mission to examine and report upon such schemes. When this commission had 

 rendered its report, a Central Board, consisting of members of the Local Govern- 

 ment Board, assisted by members elected from the various County Boards within 

 the basin, should be created for the purpose of dealing with the water supply of 

 each river basin. This Board should have rating powers over the whole basin, and 

 the conservancy of the rivers, and would contain the elements for dealing with cases 

 in which the requirements exceed the resources of the basin, and vice versd. 



* Published in extenso by the Committee of Section G. 



