12 
BULLETES 
'. U. 
DEPAE1MEXI JE 4GBHHJLTTJBE. 
Fte. ::.— "VTeHDrotr :"::;. 
as from the center. The outer edge should be raised : form 
a trough emptying into a tight drain, or a drain trough should be 
i Led t catch the drip. E. Bartow 1 suggests tnat the eart:: I e 
d for 4 : 31 utsi . i feb i .creasing I leptb f4l i 
and that an extra 4-ineh coating of waterproof Portland cement in 
fcsidc this si g with 4 to I Laches f mortal in tin I t- 
tom of the excavation. This bottom should have a raised portion a i - 
:-rt these-. _ w fcerl talc brain. Tnisarra ig m 
Ltssuri r that has not been niter ed thro v. gh :-: least 4 feet 
: arth from gai 
— ;o the w UL 
Figure 10 shov- 
combination of th se 
protective am:. . - 
ments . 
Springs re g I 
sources >f water si - 
ply. since they usu- 
ally come from _: 
fcbs within rock or are filtered through many layers of sand and 
si However, they are subject : pollution from the - 
sources as wells and should :: closelv watched in (his respect. 
Farm spring - fies :- ften . Quted by the drainage fro:., bui] l- 
i gs and si k us. Spring water supplies fro::: hmesl n< are Isc 
subject to pollution from distant garbage and sewage dumps in sink 
les, as show:, in fig- 
Hie same pre- 
ions should be 
d : : saf< _ 
i _ -pringsupph- - - 
in the case of wells. 
and in addition the 
sunns: should b ys 
be fenced to keep < 
:. It should I D trash and walled in to form a kind 
s r? ir, as shown in figure 11. The supply may then 1 ;condi 
to the house t _ vity or by means of a hydraulic ram. Where a spring 
issmaD I rge vitrified tile ma; - placed as t( : n small si ragi 
? ir. The : - rv ir should be covered and protected as much 
ssible from filth and vermin. Aftei rains the s] ring should be 
fci ed for any sk r us of turbiditv which mav indicate polluti 
. . . i 19 
