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A swimmirg pool lined with the glazed tile referred to above is showa 
in Fig. 1, Purdue University Memorial Gymnasium, 1909. 
In addition to the outlets for the water in the bottom of the pool, it 
is advisable to have, at the overflow point, a suflticient number of outlets, 
or a trough extending all around the pool, so that when a scum or dirt 
collects on the surface of the water, the upper layers may be drawn off 
without necessarily emptying the whole pool. 
Fig. 2. Men’s Swimming Bath, Leeds, England. (Lighted by sky-light only.) 
By courtesy of ‘Modern Sanitation.” 
The floor of the pool room should be so drained that water dripping 
from bathers who have come out of the pool can not collect in puddles, 
and, furthermore, such water should drain, not back into the pool, but 
into the overflow waste pipes. 
THE WATER SUPPLY. 
The water supplied to the swimming pool must be pure, and every 
possible means used to keep it so during and after its use by the bathers. 
The nearest approach to an ideal water supply for an indoor swimming 
pool would be the provision for a pure water to start with, and a continu- 
ous change of water, during the use of the pool, the rate of this change 
being governed by the number of bathers in the pool. In most cases this 
is out of the question on account of the expense. 
The water of these pools is not exposed to the many purifying fac- 
tors that affect out-door waters. The pool is usually located in the base- 
ment or in buildings the interior of which the direct rays of the sun 
seldom reach. Thus one of the most important factors in the purification 
of natural waters is removed. It is true that the water does get some 
