440 THE POPULAR SCIENCE MONTHLY. 



our Jowetts and our Stanleys, not to mention other "brave men, who 

 see more clearly the character and magnitude of the coming struggle; 

 and who believe undoubtingly that out of it the truths of science will 

 emerge with healing in their wings. Such men must increase, if the 

 vast material resources of the Church of England are not to fall into 

 the hands of persons who may be classed under the respective heads 

 oiweak and infatuated. 



And now I have to utter a "farewell," free from bitterness, to all 

 my readers thanking my friends for a sympathy more steadfast, I 

 would fain believe, if less noisy, than the antipathy of my foes ; com- 

 mending to these, moreover, a passage from Bishop Butler, which they 

 have either not read or failed to take to heart. " It seems," saith the 

 bishop, " that men would be strangely headstrong and self-willed, and 

 disposed to exert themselves with an impetuosity which would render 

 society insupportable, and the living in it impracticable, were it not 

 for some acquired moderation and self-government, some aptitude and 

 readiness in restraining themselves, and concealing their sense of 

 things." In this respect, at least, his grace the Archbishop of Can- 

 terbury has set a good example. 







WATER-SUPPLY OF ISLANDS. 



By FKANKLIN C. HILL. 



ON islands of considerable size and height, composed of rocks and 

 various earthy beds, springs of fresh water in the valleys are not 

 uncommon, and their presence excites no remark. The rainfall of the 

 island itself is laid up in its strata exactly as in the hills of the main- 

 land, and the small size of the reservoir is made up for by the frequent 

 rains and fogs to which islands are subject. 



There are cases of islands near the main-land where springs are fed 

 by streams from the continent following the rock-strata below the di- 

 viding straits. But on islands composed as many of those on our 

 Southern coasts are, of pure sand and of very small elevation, and 

 hence with no raised reservoir to supply springs, the fact that pure 

 fresh water may be obtained in large quantities by digging, is a mys- 

 tery even to many well-informed people, although the explanation is 

 very simple. To say that the " sea-water filters through the sand into 

 these wells and becomes as sweet and pure as spring-water," is simply 

 to display profound ignorance of chemistry and facts. 



From time immemorial the ash-leach has been in use in many civil- 

 ized, that is, soap-making, countries. Essentially an ash-leach is a 

 vessel tight enough to hold wood-ashes, but not tight enough to hold 

 water. Being first filled with ashes, water is then poured in gradually, 



