238 The Philippine Journal of Science 1921 
terland,” or back country. The interior is high, rugged, and 
sparsely inhabited. 
Near the sea, in places within a few meters of it, runs a 
first-class macadamized highway and, parallel with this man- 
made highway and the sea (the cheapest highway of all), a 
railroad has been built which has a spur running up to the 
Danao-Compostela coal field. Except the freight to and from the 
mines there is very little to haul over this railroad. Had it 
not been for the Government guarantee of 4 per cent, this 
venture would have been a great loss to the investors. A 
railroad cannot, except under unusual conditions, compete with 
transportation by sea, and it must have productive back 
country to feed it. 
Although Magellan discovered the Philippine Archipelago by 
first landing at Cebu and although a large and prosperous city 
is there to-day, the physiographic advantages of the position of 
Manila are so superior that it has been able far to outstrip 
its southern rival, notwithstanding the fact that Manila as a 
Spanish city was not founded till nearly a half century later. 
Cebu is a distributing point and has to draw upon neighboring 
islands. In Manila we have a remarkable juxtaposition of 
sea, excellent harbor, river, mountain, and plain (affording a 
productive hinterland) which has led to the development here 
of what is fast becoming the most important city of the Orient. 
Seismology.—Earthquakes are not confined to the Tropics. 
Nevertheless, many regions of great seismic disturbances are 
either within the Tropics or not many degrees removed. There 
may or may not be any direct connection between these facts. 
It also happens that many of the geologically newer parts of the 
earth are within this zone. In view of the great engineering 
works built at Panama, in the Hawaiian Islands, in the Philip- 
pines, and elsewhere it is of prime importance to understand 
the principles controlling earthquake phenomena. The damage 
done at San Francisco by the slip along the San Andreas rift, the 
catastrophes of Messina and Avazzano, and the lesser disturb- 
ances that have occurred in the Philippines from time to time 
should force us to pull our heads out of the sand and look facts 
squarely in the face. Real estate boosters as a rule do not readily 
fall in with this idea. ; 
For the benefit of the possible lay reader a few elementary 
facts are here repeated. Earthquakes are due to three causes; 
namely, rockfall, vuleanism, and slips along fault planes. These 
