164 | ANNUAL REPORT SMITHSONIAN INSTITUTION, 1946 
buster is to the blunderbuss. Yet even the present atomic bomb is a 
highly effective weapon. If one bomb will devastate four square 
miles and damage a hundred square miles, how many bombs are 
needed to destroy all of a nation’s concentrations of fighting and in- 
dustrial facilities above ground? Will it be 100, 1,000, or 10,000? 
That is a question for the military to answer. It has been demon- 
strated that whatever bombs are required can be produced and de- 
livered to their targets. 
Let us try to imagine what may be expected to happen if a war be- 
tween two major powers should break out in 1970. We may assume 
that by this time both sides will have such weapons in whatever 
amount they consider necessary and of greater destructiveness and 
variety than those now possessed by the United States. Because of 
the enormous advantage of surprise, Pearl Harbor tactics will be 
employed. Jet-propelled planes or rockets with atomic warheads 
will be sent without warning at each of several hundred of the enemy’s 
major production centers, No city of over 100,000 population will 
remain as an effective operating center after the first hour of the 
war. At least 10 percent of the attacked nation’s population will be 
wiped out in the initial blow. If this nation elects to fight back, 
rockets and planes from hidden installations will carry the reply. The 
attacker in this case can expect no mercy. Though his citizens may 
have immediately moved underground, his great cities as well as his 
surface production plants will be annihilated. The fighting will con- 
tinue until one side chooses to surrender or is unable to resist its 
opponent’s army of occupation. 
If the United States should be party to such a war, we should ex- 
pect Philadelphia, with such neighboring cities as Reading and Wil- 
mington, to follow Hiroshima and Nagasaki into oblivion. With the 
destruction of these cities we should expect about one out of every four 
of their inhabitants to be killed. If our Nation should eventually win, 
what would we have gained? Perhaps the control of the world. But 
of what value would this be with our civilization gone and our popu- 
lation decimated ? 
No feasible means of preventing the bombs from striking their tar- 
gets has yet appeared on the horizon. Only two countermeasures have 
so far been proposed. The first is to disperse our cities, preferably into 
hilly regions, so that more bombs will be required to destroy them. 
The second is to place all military installations and essential in- 
dustries underground and provide emergency underground shelters 
for all the population. Clearly such measures will seriously interfere 
with our normal life. So indeed was it inconvenient in the middle 
ages to live in a castle on a hilltop; but safety in a world of robbers 
