200 
The North Atlantic ports from which the major part of the gen- 
eral manufactures will be sent will also be exposed to such dis- 
ease exchange. 
It is predicted that after the isthmian canal is completed, a 
large part of the world's commerce will be done by tramp steamers. 
It is probable that nowhere will the use of tramp steamers be 
found more profitable than in the Pacific Arena. 
Such steamers will carry coal from Australian and Japanese 
ports to every other port in the Pacific Arena. If the mines of 
China are ever developed, coal may be shipped by tramp steamers 
from Chinese ports to all parts of the Pacific Arena. This pros- 
pective intercourse between Chinese and other Pacific Arena ports 
by means of tramp steamers will tend to increase to a marked 
degree the chances of. the interchange of the quarantinable dis- 
eases, as the tramp steamer as a rule is more likely to become in- 
fected than either passenger steamers or sailing vessels. 
It is claimed that Japan's industrial revolution has only begun, 
and that she will require more and more of the products of the 
United States. As the South Carolina phosphates, iron and steel 
fixtures, raw cotton, leather goods and flour will probably come 
through the Panama Canal, and the raw silk from Japan go back 
by the same route, the danger of the interchange of quarantinable 
diseases between the Southern States and Japan will be still fur- 
ther increased. Although Japan is very efficient and progressive 
both in her internal sanitation and quarantine, her steady imports 
from China of rice, cotton, beans and peas will be a constant 
source of danger from infection with quaratinable disease. All 
signs point to the trade interchange between the United States and 
South America becoming from a quarantine standpoint somewhat 
similar to that between the United States and China. The reason 
for this lies in the fact that Chili will buy from all parts of the 
world, and on account of her return cargoes of nitrates, ores and 
heavy produce will probably become infected with all of the quar- 
antine diseases. 
The ports of Xorth America* Vancouver, Seattle and San 
Francisco are known from a quarantine standpoint as "tourist and 
immigration ports." 
Doutbless after the isthmian canal is completed Port Townsend, 
Portland, Los Angeles and San Diego will be similarlv designated. 
These "tourist and immigration ports" are the eastern termini 
of the principal passenger and freight lines which ply between the 
Occident and the Orient. A large number of tourists pass 
through these ports every year, en route to or from the Orient or 
Australasia. 
The tourist is an important factor in quarantine work in the 
Pacific Arena, because such a person is invariably bound for or 
returning from the principal disease centers, and his object, the 
observation of foreign places, people and customs, and the pur- 
chase of articles of interest, entails an unusual and marked con- 
