BY J. BROWNLIE HENDERSON AND H. WASTENEYS. 47 
is saturated with oxygen. By this arrangement of controll- 
ing the supply first from the storage tank as to quantity, 
and secondly, from the cistern as to rate, we have found 
that the filter works quite automatically. It has been 
in use for over twelve months with no attention, save that 
on one occasion, after running nine months, the top quarter- 
inch of sand on the filter was removed and thrown away. 
The storage tank, filter and cistern were covered, and made 
mosquito proof, and the inside of each painted with 
“ bitumen ”’ paint. 
The chemical analysis of the filtered water shows 
that there is always a large decrease in the albuminoid 
ammonia and in the “ oxygen consumed,” and the color is 
almost entirely removed Saprophytic bacteria only are 
found in the filtered water, averaging from 50 to 100 per c.c. 
The intestinal bacilli, especially coh communis, are always 
present in the main supply, but have never been found in 
the filtered water On one occasion, when the Brisbane 
River wasin high flood, and dark brown, muddy water was 
being supplied, the filtered water was slightly opalescent, 
and had a yellowish colour, but that disappeared in a week. 
As a result of the use of this filter, there is always on 
hand a supply of 600 gallons (the capacity of the storage 
tank) of pure, clear filtered water, which is used for drinking, 
cooking, and the bath. The advantages of a pure, clear 
water supply need not be pointed out—they have been 
well-known for many years. By the use of a filter of this 
kind, which only costs comparatively a few pounds, such 
a supply is always assured, while none of the small domestic 
filters generally in use, although requiring constant atten- 
tion, can give a supply for the kitchen and bath room, 
very few of them remove the bacilli present, and a large 
proportion of them serve as breeding grounds for objection- 
able microbes. 
