DAY — WATER SUPPLY. 
65 
They prove however that all the waters are fit for drinking 
purposes, more especially that from the Morocoy Spring. 
The sample from the Moriehal Spring contained a large 
amount of lime, although collected at the best time in the 
year for its purity. The quantity was so great in fact that 
I am afraid that the pipes employed to carry the water to 
San Fernando from the hills would, before long, become 
choked with a deposit of the insoluble carbonate of lime, 
which would inevitably be separated from the water on 
exposure to the air for any length of time. This might 
however be easily obviated by treating the water in the 
collecting reservoir by a process called Clarke’s process, by 
means of which all the lime present in the water, and 
expressed iu the following analytical table as temporary 
hardness, would be removed. This process could easily be 
carried out at Montserrat, and could aiso be readily and with 
but small expense applied to the supply at Port-of-Spain. 
The principle on which it is founded is that the lime which 
exists in the water, and can be removed by boiling, is 
simply held in solution by the presence of free carbonic 
acid, and that as this carbonic acid can be converted into 
an insoluble compound, both it aud the lime which it holds 
in solution can easily be removed from the water. To 
effect this we make a careful examination of the water to 
find out the amount of lime thus held in solution, and then 
add to the known volume of water just sufficient quicklime 
to combine with the whole of the free carbonic acid, and 
so convert it into an insoluble carbonate of calcium, which 
soon settles down and leaves the clear purified water 
above it. To carry out the process we should re- 
quire to build a double set of reservoirs, each capa- 
ble of holding at least one week’s supply for the town. 
The process of precipitation and settling of the deposit 
