is,3 Smith: Tropical Geology and Engineering 241 
importance. The work of the Italian geologists in Calabria 
and Sicily in this particular field of investigation has given 
us a fine example of what to do and how to do it. 
Finally, as volcanic eruptions and tectonic earthquakes may 
both be connected with deep-seated phenomena in the earth 
magma, it behooves us to proceed vigorously and continuously 
with detailed volcanological studies along the lines laid down 
by Perrett, of the Vesuvius Observatory; Omori, of Japan; and 
Jagger, of the Volcano Observatory of Kilauea, Hawaii. If 
we do this we shall have a collection of data which in time will 
enable us to cope with these dreaded phenomena as we now do 
with the typhoon. 
SUMMARY 
1. The geological agents at work in tropical regions are the 
same as those found operating in temperate parts of the earth, 
with the difference that they are often greatly accelerated in 
the former. 
2. In the Philippines structural conditions are of prime 
importance in engineering. Both major and minor faulting 
occur here which as yet have not caused trouble save in mining 
operations. 
3. Both road location and maintenance in tropical countries 
like the Philippines are much more difficult than in the United 
States and Europe. 
4. Dams and reservoirs should be avoided when possible in 
countries like the Philippines. 
5. The instability of the Philippine geological structure is 
established. 
6. Weathering of the rocks in tropical regions is notable. 
The so-called laterite, in some places of considerable economic 
importance, is a product of weathering. It is characteristic 
of many tropical countries. 
7. The geologic work of organisms is great in the Tropics, 
though but little studied. 
8. The work of tropical rain and running water is not 
appreciated as it should be. 
9. Handbooks and formulse prepared by engineers acquainted 
only with conditions in temperate regions are worse than useless 
in the Tropics. They are positively dangerous. 
10. Engineers as a whole should, if possible, give more 
attention to the study of modern geology which is no longer 
merely a descriptive subject but is becoming more and more 
a close relative of engineering. 
