06 REPoni — 1884. 



Tenth Report of the Committeo, conslntui;/ of Professor K. Hill, 

 Dr. II. W. Chosskkv, Caytain Doucjlas (ialton, I'rofl'ssors .1. 

 PuKSTWiCH and (J. A. Lf.iioi^h, rt7?(^ Messrs. Jamks Glaisiikh, K. 1?. 

 Mahtk.n, (r. II. Moi{ton,Jamks Paukkk, W.Pknoklly, James Plant, 



I. JiOHKHTS, Vox STHAN(i\VAYS, T. S. StoOKK, (r. J. SyMOXS, 



\V. Toi'LLV, TYLDKN-WiiUiiiT, !«'. Wktiikrki), W. Whitakkk, 

 and C. K. I)k Kanck {Secretary), appointed for the purpose 

 of invent if/at I ni/ the Circulation of Undenp'onnd ^Vatern in the 

 Pemaeahle Formation.'^ of J'Jii(/land and Wales, and the Qaantit/f 

 and Character of the Wider mippUed to various I'oivns and 

 Districts from, those Formations. Drawn up by C E. 1)k Kanck. 



The Chairman and Scorctniy of your Conimittco are both unavoidahly 

 oblip;ed to be absent at tlie Mdnti-ciil iiiceliiif,', whicli is a source of regret 

 to tliemselvcs ; tlio more so tliat, tliis hulu^' flio case, it has been tliought 

 advisable to delay presenting their linal Jloporfc on tbo Circulation of 

 Underground Waters in South Britain until next year, when the Com- 

 mittee will have been twelve years in existence. During these years 

 particulars have been collected of the sections passed through by a very 

 large number of wells and borings; a daily record has been obtained 

 of the height at which water stands in many of these wells ; invcstiga^-ions 

 have been carried out as to the <]uantity of water held by a cubic foot 

 of various rocks, by Mr. Wethcred ; and as to the filtering power of 

 Bandstones, and the influence of barometric pressure and luiuir changes 

 on the height of underground waters, by Mr. I. Roberts. During the 

 present year the attention of the Committee has been directed to the 

 remarkable influence of the earthquake which visited the east and east- 

 central counties of England, in March last, in raising the levels of the 

 water in the wells of Colchester and elsewhere. 



More detailed information is still required as to the proportion of actual 

 rainfall absorbed by various soils, over extended periods representing 

 typical dry and wet years. Information on these heads and on other points 

 of general interest bearing on the percolation of underground waters, 

 referring to observations made in Canada or the United States, would be 

 gladly welcomed by the Committee, and would be incorporated in their 

 eleventh and final report to be presented next year. 



Appendix — Copy of Questions circulated. 



1. Position of well or .shafts with which you are acijuaintcd ? Xa, State date at 

 which the well or shaft was ori;;inally sunk. Has it been (leopeiierl since by sinkin<? 

 or borinf; ? and when ? 2. Approximate height of tlie surface of the ground above 

 Ordnance Datum (mean sea-lcvcl) ? 3. Depth from the surface to bottom of shaft 

 or well, with diameter. Depth from surface to bottom of bore-hole, with diameter/ 

 3a. Depth from \\\i\ surface to the horizontal drift-ways, if any ? What is their 

 length and number .' 4. Height below the surface at which water stands before and 

 after pumpin<:i; ? Number of hours elapsine- before ordinary level is restored after 

 pumping ? 4rt. Height below the surface at which the water svood when the well 

 was first sunk, and licight at which it stands now when not pumped? 5. Quantity 

 capable of being pumped in gallons per day of twenty-four hours ? Average quantitj- 

 daily pumped ? 6. Does the nater-lerel vary at different seasons of the year, and to 

 what extent ? Has it diminished during the last ten years ? 7. Is the ordinary 

 tvatcr-lcrel over affected by local rains, and, if so, in how short a time ? And how 



