BY THE HON. W. F. TAYLOR, M.D., ETC. 33 



which percolates through the aerial outcrops of the porous beds 

 of the Lower Cretaceous formation on the western slope of the 

 coast range. Local contamination of the rain water on or near 

 the surface of the ground could have no appreciable effect on 

 the great bulk of water which had percolated or filtered through 

 the porous strata mentioned. Li its passage through these 

 permeable strata, however, it would dissolve and hold in solution 

 more or less mineral matter ; so that, as a rule, artesian water 

 is rich in saline and other mineral constituents. Norton's 

 Abyssinian tubes form a very valuable means of reaching water- 

 bearing strata at a moderate depth, and have much to recom- 

 mend them from a sanitary point of view. 



The cause of the water in artesian wells rising above the 

 surface, is mainly, if not entirely, due to its coming from a 

 higher elevation than the mouth of the well. 



Rain water impounded from roofs of buildings and stored 

 in tanks, is a very common source of domestic water supply in 

 this country. The water so obtained varies in purity according 

 to the freedom or otherwise of the air from dust and ammo- 

 niacal and sulphurous gases, and the roofs from dust, leaves, 

 droppings of birds, &c. Dust blown from the streets and yards, 

 and deposited on the tops of houses may, and often does, contain 

 organisms of a pathogenic nature. It becomes very necessary, 

 therefore, that provision should be made to prevent the first 

 washings from the roofs gaining access to the storage tanks. 

 An ingenious contrivance to accomplish this object is Roberts' 

 Percolator. The apparatus is balanced on a pivot and connected 

 with the downfall pipe so that as soon as the pure water com- 

 partment is filled to a certain point it cants over, and the water 

 runs clear to the storage. At my suggestion the Hon. Sir 

 Samuel Griffith, when Premier in 1886, ordered a consignment 

 of sanitary appliances from London, to serve as models for the 

 use of the Local Authorities here, and, amongst the lot was one 

 of these percolators, which no doubt is still in existence, but 

 where, I do not know, as little or no care has since been taken 

 of the appliances then imported, which were subsequently 

 stowed away somewhere as so much useless lumber by those 

 whose duty it was to look after and care for them. A resident 

 of Toowoomba, named Irwin, invented a very simple and much 



