Miscellaneous. 



68 



[<July, 1911. 



the practical result, which is well known 

 to the inhabitants, is that well sinking 

 is an absolute certainty, and, given a 

 knowledge of the surface levels, the 

 depth to which a well must be sunk is 

 known to an inch. 



Also, the flow from a well or any 

 similar cavity sunk below the water 

 plane is exactly in proportion to the 

 superficial area of the cavity at a given 

 average depth below the water plane. 



It may be useful to note that for small 

 depths below the water plane the flow 

 from the Jaffna rock formation in a well 

 of 14 feet diameter and 25 feet depth to 

 the water surface from ground level is 

 such that one ordinary " well sweep" 

 cannot reduce the water level more than 

 about 4 feet when kept continually 

 working, and this represents a total 

 quantity of 17,000 gallons in a 10-hours' 

 working day, equal to, say, 2,700 cubic 

 feet of water, or, say three-quarters of 

 an inch deep over an acre. 



13. In conclusion, it may be said that 

 the term " well " is one which is used to 

 describe any cavity in the earth's surface 

 which is sufficiently deep to reach the 

 water plane, and passes through all the 

 various phases between the mere water 

 hole and the tube bore, embracing also 

 all the usual variations in size, shape, 

 and methods of lining with timber, 

 brickwork, masonry, &c. 



To enter into a description of all these 

 technicalities is beyond the scope of 

 such a paper as this, but a general 

 principle which must always be kept in 

 view may here be stated, namely, that 

 the larger the superficial area of the 

 opening below the water plane, the 

 greater will be the supply obtainable in 

 any one place, and that most wells 



require either partial or complete 

 "steining" or lining with brick or 

 masonry. 



When the quality of the water and 

 freedom from contamination is import- 

 ant, then this masonry lining should 

 be built solid in mortar for several feet 

 below the surface, and without mortar 

 when the water plane is reached. If the 

 subsoil below the water plane is pure 

 sand, it may be necessary to plug the 

 bottom of the well with concrete to 

 prevent the sand being drawn up into 

 the well, and possibly the sinking of the 

 lining as a consequence, and this parti- 

 cularly where large quantities of water 

 have daily to be extracted. 



Care should, however, be taken to 

 avoid following the precedent supplied 

 by a case which came to the writer's 

 knowledge some years ago, when on 

 examining a well (masonry lined) situ- 

 ated in a position where the subsoil was 

 most undoubtedly water-bearing, it was 

 found that the bottom of the well had 

 been plugged with concrete, as above 

 described, but in addition, to make 

 matters more comfortable, the whole 

 of the masonry lining from too to bot- 

 tom had been built in brickwork in 

 cement mortar, thereby effectively ex- 

 cluding all entrance of water, and the 

 inside being as dry as a drum. The 

 writer gained considerable "kudos" 

 locally, added to a subtle suspicion of 

 the supernatural, by making the water 

 flow. This was not a difficult operation, 

 involving only the boring of three or 

 four holes in the concrete bottom and 

 firing a dynamite cartridge in one of 

 them. 



R. W. SMITH. 



Trincomalee, March 25, 1911. 



THE CEYLON AGRICULTURAL SOCIETY. 



Statement op Receipts and Expenditure for 12 Months Ending Dec. 31, 1910. 



Amount. Total. 

 Receipts. Rs. c. Rs. c. 



Balances at Bank of Madras, 



&c, December 31, 1909 — 43,073 93 



Members' Subscriptions : — 

 Local subscriptions for 1908 257 

 Do 1909 763 



Do 1910 4,059 40 



Do 1911 444 



Do 1912 16 



Foreign subscriptions 394 50 

 Less paid to Ceylon 



Observer ... 295 87 



Life members' subscriptions 



Government grant for 1910 ... 

 Interest : — 

 On Bank of Madras account 



98 63 

 50 



5,688 



— 30,000 



— 788 52 



Payments, 



General Expenditure :— 



Organizing Vice- Bs. c. 

 ► President ... 3,000 00 

 Secretary ... 3,000 00 

 Clerks and peons 2,715 37 

 Agricultural In- 

 structors ... 2,326 63 



Amount. 

 Bs. c. 



Total ... 79,550 48 





11,042 







Stationery 



241 



98 



Postages and telegrams ... 



722 



44 



Office furniture 



230 



22 



Bank charges and commis- 







sion 



17 



95 



Micellaneous petty expen- 







ses 



426 



10 



Auditors' fee for 1909 ac- 







counts 



150 







Advertising ... 



3 







Total, 

 Rs. c. 



12,833 60 



