sun-worship when lying unclothed upon highly reflective beaches. 
A cynic has said that language was invented by man to conceal his thoughts, 
but the development of the avenues of communication has lead to the advance- 
ment of knowledge. 
So, as communication between the wise men grew, knowledge was gradually 
dispersed among the old civilizations and, with the growth of new ideas so born, 
the old empires fell and gave place to new. Hence the old Chaldean, Persian and 
Egyptian Empires were succeeded by the Greek, the Carthagenian, and the 
Roman Empires, and during these new eras philosophy was born and grew, and 
logical consideration of the physical facts of the universe began to be recorded. 
It was soon realised, that while the sun had much to do with the growth of plants 
and the ripening of crops, its influence was not of a supernatural nature, but was 
physical or chemical in its action. 
The early Christian era preceded and followed the fall of the Roman Empire. 
In this stage of the development of civilisation most of the ancient knowledge was 
repudiated and forbidden. Right up to medieval times the Church had practically 
the sole control of education and thought, and any attempts to pry into the un- 
known were regarded as dealings with “the devil,” and were suppressed by the 
invocation of curses, with all the dread ritual of bell, book and candle, and by the 
infliction of physical torture and death. But while the Church was refusing any 
adventure into the unknown, it was sowing the seeds of the growths which later 
would strangle its power, for it was imparting the rudiments of reading, writing 
and numbering to the children of its adherents, and, when the fruit of the Tree 
of Knowledge is eaten, its seeds fall to the earth and germinate and grow. With 
the Renaissance there came a fresh growth of speculation and investigation into 
the phenomena of the earth, and, although most of these early researches were 
abortive, some of them survived to form the basis of modern science. 
Among the many phenomena to which thought was given in those early 
times was that of “Light.” Many theories were evolved regarding the nature of 
the sun’s rays, but the first man to give any practical pronouncement was the 
great English Scientist and Mathematician, Sir Isaac Newton, of whom all that 
most of us know is the legend that an apple struck his head, and, as he couldn’t 
find anyone who threw it, he propounded the Law of Gravity to explain the event. 
Newton made many experiments with lenses and prisms, and he demonstrated 
that white light—the light which we see and which we know comes from the 
sun—was not an intangible essence but something which has physical attributes, 
and which could be divided into various constituent parts—and from the further 
investigations which have followed upon Newton’s work right down the cen- 
turies to the present day, we know that the sun’s rays can be weighed and analysed 
and controlled, like all the other phenomena which make up our wonderful uni- 
verse, 
As a result of these investigations, we now know that visible light is but a 
fraction of the constant radiation from the sun—how small this fraction is can be 
seen from the diagram opposite. This gives some idea of the composition of the 
rays as they leave the sun. This radiation is made up of a number of different 
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