THE SUN’S ENERGY—DANIELS 239 
An occasional catastrophe has shown the helplessness of industrial- 
ized cities when the electricity goes off. Every year it becomes more 
difficult for them to exist without abundant power. The people 
could not spread out to the farms and live at a subsistence level. The 
farms are mechanized, too. I have recently had a survey conducted 
by V. Stoikov who found that for every calorie obtained from food 
in the United States, we put a little more than a calorie from fossil 
fuel into producing the food. 
Another important factor in our rising interest in the sun is the 
realization of the great need for more mechanical power in the non- 
industrialized areas of the world. Transportation and communica- 
tion have improved so much that we are acutely aware, as never before, 
of the need to give technical help to our friends on the other side of 
the world and to the south of us. 
I was privileged to attend a solar-energy symposium in 1954 in 
New Delhi, as a guest of the Indian Government and UNESCO. The 
Indian Government took us on a study tour of the semiarid regions. 
We saw, among other things, four bullocks and two men working dili- 
gently and skillfully for long hours irrigating farmland. Every min- 
ute two bullocks pull up by rope 250 pounds of water from a depth of 
50 feet. One of the men collapses the water bag made from hide and 
the water flows over the land. The second operator drives the bullocks 
and a second team of bullocks pulls up the next 250 pounds of water. 
This work done by the four bullocks and two men is reckoned to be 
equivalent to one-third of a horsepower. And the four bullocks cost 
$600 and have a life of only about 6 years. Moreover, they have to eat 
and they must consume a considerable portion of the crops that they 
help to grow. The project seemed to be barely self-supporting—but 
the water has to be raised. If the bullocks’ walkway were covered 
with a solar heat collector which activated a crude engine working at 
only 5-percent efficiency, a 1-horsepower pump could be operated. 
Five-percent efficiency should not be impossible. The challenge to 
replace these bullocks with solar engines seems more important to 
me now than some of the theoretical researches in which I have 
been engaged. (Of course, the bullocks are used for plowing and 
transportation as well as for irrigation.) We also saw a camel walk- 
ing around a well and pulling up water by a rotating mechanism. 
We saw a man getting water with the help of a counterweight, and 
a woman walking back and forth on a balanced beam to pull up 
pails of water. Solar engines certainly cannot compete yet with coal, 
oil, and electricity where these are abundant, but I believe that it 
should be possible to compete right now with manpower and animal- 
power, in areas where fuels are available only at high prices. 
The economics of solar energy does not look very attractive as 
yet in fuel-rich, highly industrialized areas, but it should be attractive 
