a See) 
PROCEEDINGS OF SECTION H. 679 
obtained by opening windows, doors, fireplaces, and ventilators. 
But the unpleasant nights passed were largely due to the heating 
of the roof and walls by the sun, and it was this heating which it 
was essential to avoid. This he had done by painting the roof 
and exposed walls with a white paint. Simple experiments 
undertaken to show the difference caused by painting the slates 
resulted as follows :—The temperature of a painted slate at mid- 
day on a bright summer’s day was about 30 deg. lower than an 
unpainted one. The interior of flower-pots and boxes covered by 
slates exposed to the sun at the same time of day differed by 
from 10 to 18 deg. A house with roof and walls painted was 
probably 10 deg. cooler than an unpainted one. Consequently, 
to keep a house cool it was simply necessary to paint the roof and 
walls, to keep all doors, ventilators, fireplaces, and windows shut 
in the warm part of the day, and to open them at night. The 
use of the electric light would greatly assist. If coolness was 
desired on the few nights on which the air was hot, special venti- 
lating apparatus must be provided. In the house in which he 
(Dr. Barrett) lived, when the directions had been followed, the 
temperature had not exceeded 76 deg. F., and was rarely above 
70 deg. 
- 4.—PURIFICATION OF SEWAGE. 
By J. M. Smaiz, M.Inst.C.E., and W. L. p—E L. Roserts, C.E. 
In his work on “Health and Life” B. W. Richardson, M.D., 
F.R.S., states that “An ancient ruler, no less ancient and no less 
cunning a ruler than Cambyses himself, taught his son Cyrus 
certain lessons in sanitary science, which he then considered much 
needed, and instructed him as to his chief anxiety in connection 
with his army, which should be the preservation of health; for, 
says Cambyses, he should prevent the army falling into sickness 
at all.” In addition to the above advice, he adds other observa- 
tions, which shows to us that in Cambyses’ day (529 B.c.), in the 
midst of a very high ancient civilisation, there was no special 
exemption from the thousand natural ills that flesh is heir to. 
The advice given by Cambyses to his son can well form a 
subject worthy of serious consideration by those in authority and 
charged with the well-being of communities forming a State. The 
ancient law-giver (and no less a sanitarian) Moses enjoined upon 
the Hebrews the “ necessity of disposing of the excretions of the 
human body and other organic filth by burying the same in the 
earth at places remote from habitations, without the camp.” 
“Under the Mosaic dispensation sanitary laws were religiously 
observed, and recent discoveries clearly show that the ancient 
Jews possessed a clear knowledge of the necessity of removal of 
