250 REPoR'D — 1875. 



returns of the Medical Officers of Health, to be insufficiently or improperly supplied, 

 the author proposed to utilize the maps of the Government Geological Survey, 

 now nearly complete, for the districts referred to, and on which the areas of the 

 water-bearing and impermeable formations respectively are accurately laid down. 

 With the aid of these maps (which were easily obtainable) it could be determined 

 by the Local Sanitary Authority whether any special village or hamlet was so situ- 

 ated as to be capable of receiving a supply by a well of reasonable depth. In case 

 of necessity, however, professional advice might be called in ; but the author con- 

 sidered that, owing to the special nature of such cases, it would be necessary to 

 have a geologist of experience attached to the Central Board of Health, whose duty 

 it would be to advise with each Local Sanitary Board as occasion might arise. 

 This officer should also assist in the selection of a proper site for a well, and aft'ord 

 data for determining the depth and cost of sinking, &c. 



Upon the report by the Officers of the Local Board of Health, certified by the 

 Government Adviser, of the feasibility of a plan of water-su)3ply by a well or bore- 

 hole, an order should issue for the compulsory carrj'Lng out of the work, and powers 

 should be vested in the Local Sanitary Authority to raise money for the purpose. 



The well thus constructed should be carefully preserved from pollution, and bo 

 accessible to the inliabitauts of the village or hamlet comprised in the order; and 

 all objectionable or impure sources of supply should be destroj'ed or stopped up. 



In cases, on the other hand, where it is foimd that, owing to the position of any 

 village or hamlet in reference to the subjacent water-beai-iug fonuation, the depth 

 and cost would be too great for the resom-ces of the inhabitants, then it woidd be 

 necessary to have recourse to the most suitable sti-eam or brook, which should be put 

 under strict regulation as regards the prevention of contamination. The author 

 proposed that in such cases small tanks should be constructed for storage of the 

 waters in winter, and should be vested in the Local Sanitary Board, who should 

 be responsible for their due preservation. 



In conclusion the author expressed his opinion that tlie time for carrying out 

 some general scheme of water-supply for the too greatly neglected villages and 

 country parishes had come, and which he considered might be earned out by com- 

 bining the information to be derived from Geological Survey maps with the power 

 granted under the Public Health Act of 1872. He considered that any scheme to 

 be of use should be both compulsory and of general application. He also considered 

 that until every village and hamlet, as well as every to\vn and city, had a constant 

 supply of pure water for domestic purposes, sanitary legislation could not be consi- 

 dered to have oflected its purpose. 



On a Seivcr-Traj). By Hexry Masters. 



On the Severn Tunnel. By Chaeles Bichakbson, C.E, 



On the Tidal Scour in the Severn. By Charles Richardson, C.E. 



Tides in the Irish Sea. By James N. SHootBEED, C.E. 



At the Easter equinoctial tides in 1875, a series of simultaneous observations 

 were carried on at several points on the English and Irish coasts of the Irish Sea, 

 on March 31st and on April 8th, the calculated least neap and the greatest spring 

 of the year. 



On the English side, at Whitehaven, Barrow, Fleetwood, Liverpool, and Holyhead, 

 and on the Irish one at Belfast, Dundalk, and Dublin, simultaneous observations 

 were obtained, generally imder the direction of the Engineer in charge of the port. 



The English observations, taken by Greenwich time, have been reduced to a 

 uniform level of ICO feet below the Ordnance datum of Great Britain ; while the 

 Irish ones, where Dublin time was observed, were reduced to the Ordnance datum 

 of Ireland. And as the diffi?rence between each Ordnance datum and the mean 

 level of the surrounding sea has been ascertained, it is possible, by assuming uni- 

 formity in the mean sea-level, still further to compare directly the two systems of 

 levels with each other. From a general comparison of these tidal data the fol- 

 lowing conclusions may be roughly drawn. 



