In the tropics up currents were also caused by temperature differences.
Nighttime in the tropics descends with a surprising rapidity.
Production, and afterwards slavery, could be carried on only outside of the tropics.
The strange substance from the jungles of the tropics had been mastered.
On leaving Brisbane we found ourselves once more in the tropics.
It was a rain such as is never seen on Earth, even in the tropics.
It is very comfortable, sleeping out of doors, in the tropics.
One evening I wandered into a café, in a town not of the tropics but of the South of France.
But old Nelson (or Nielsen) out of the tropics seemed unthinkable.
The civilization of the tropics could have had nothing to do with it.