240 The Philippine Journal of Science 1921 
attempt to follow up these most interesting suggestions of M. 
Zeil. 
There are three things we must do in order to cope with earth- 
quakes. The most obvious thing is in the line of engineering. 
We must build structures so tied together that the parts will 
not fly into fragments, and the material must be elastic. The 
safest and cheapest type of construction is the native house of 
bamboo wherein rattan takes the place' of nails. Sand-lime 
brick securely tied to a steel frame, and reenforced concrete, are 
the most suitable for large buildings. Volcanic tuff (locally 
quarried as Guadalupe stone) is one of the best cheap materials 
I have yet seen. The walls and many of the older public build- 
ings of Manila are constructed of this stone. 
Aside from the class of building material to be used, is the 
all-important question of the nature of the ground on which large 
structures may safely be erected. The investigations of the Cali- 
fornia Earthquake Commission revealed very conclusively the 
dangers from “made ground” in regions subject to earthquakes. 
Nevertheless, in spite of their findings, of which any up-to-date 
engineer ought to have knowledge, we see right here in Manila 
large five- and six-storied, structures (it is true they are of re- 
enforced concrete) being erected on made ground or on river 
alluvium which is none too stable. Buildings of the skyscraper 
type, such as the Luneta Hotel, are nothing less than a defiance 
of good engineering sense. Piles and test borings have not yet 
been able to bottom on the Luneta. In fact, practically the whole 
of Manila is located on loose sand saturated with water. Indeed 
it is impossible to bury the dead below ground in most sections 
of Manila because of this fact. In such material large struc- 
tures are subject to settling and they do settle. Furthermore, 
since seismic waves travel with the greatest acceleration and 
amplitude in loose formations, the displacement due to earth- 
quake motions will be greatest on ground of this kind. Three 
or four stories ought to be the limit of height for buildings in 
Manila. The writer is glad to say that the city engineer of 
Manila (a Filipino) has tried to have an ordinance passed limit- 
ing buildings to five stories. This is certainly the absolute limit 
of safety in this country. 
The geologists of countries subject to seismic disturbances 
must be instructed and must be afforded ample opportunity, in 
connection with their economic work, to map the geological 
details, such as formations, contacts, joints, faults, etc., in order 
that we may have data from which to draw conclusions of 
