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interest than the paper which has just been read by Mr. Frank 
Shuman. It almost seems presumptuous to think that we can 
make a servant of the sun, but Mr. Shuman has described so 
clearly the way in which he proposes to take such a liberty with 
the sun—and, in fact, has already done so—that one is certainly 
inclined to think that even if he has not already solved the 
problem he is, at all events, on the verge of an immense 
discovery with unlimited power for good. The possibility of 
using the sun as a producer of heat and energy on this earth 
opens up a vast vista of possibilities, and the clear way in which 
the lecturer has described his process must have made most of 
us think we were hearing of something almost too good and 
too simple to be true, and we wondered perhaps why it had 
not been done before. But we know that the most simple 
things are often thought of last. You have all listened to Mr. 
Shuman’s exposition with close attention, and I am sure his 
kind consent to answer questions will be taken advantage of 
by many present. 
Mr. E. E. Green: May I ask what the cost would be for 
one of the smallest installations? 
Mr. SHuman: Well, roughly speaking, it would be about 
£31 per horse power. You could practically build installations 
down to 5 horse power, but of course it would be better to 
have one central plant of more convenient size, and then 
transmit electric power to the small places round. 
Sir J. Witson: I know parts of India where we sometimes 
want irrigation considerably more in the cold weather than in 
the hot. In the places I have in mind the sun is not nearly so 
powerful as we are accustomed to think of it in connection 
with India; in fact, itis only a little hotter than it is in England 
in the summer. Would this method be able to develop any 
useful power in such a case as that? 
Mr. Suuman: That is a very interesting question. As I 
point out in my paper, the sun does not throw heat rays on 
the earth; it simply throws light rays, and unless these light 
rays are absorbed no heat is produced. It is not a question of 
atmospheric temperature so much. If a sun-power plant were 
put up in a place where the temperature is below zero, of 
course there would be a little more loss by conduction into the 
surrounding atmosphere. In London here, on some of your 
bright sunshiny days, you could run a plant just as effectively 
as in the tropics. The only reason why a sun-power plant 
would not be effective all over the world is that in most parts 
of the temperate zone there are not sufficient hours of sunlight 
during the year. In America our very best tests were made 
when there was snow on the ground, and the temperature was 
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