92 
WORLD OF INVISIBLE LIFE 
What did they 
do at Panama? 
set to work to get rid of these mosquitoes, which 
were very numerous in the damp, warm climate 
of Panama. 
They drained the stagnant ponds and 
swamps that were the mosquito’s breeding 
places; they killed the young mosquitoes*where 
they could not drain the water, by pouring oils 
and poisons on the surface. They also built 
houses for the workmen with mosquito-proof 
screens, and put mosquito-netting over the beds 
to keep the men from being bitten while they 
slept. Those who were already sick were 
placed in carefully screened hospitals to keep 
mosquitoes from getting in and biting the men 
who already had the disease. They thus kept 
the mosquitoes from getting germs and carrying 
them to men who were well. By the use of all 
these means, they were able to stamp out ma¬ 
laria almost entirely, and the great Panama 
Canal was built, uniting two great oceans, so 
that ships could pass from one to the other. 
We can rightly call the building of the 
Panama Canal a modern miracle. It had taken 
