116 THE PRODUCTION AND USE OF HEAT 



this water. Now empty out this water and weigh the pail. The 

 difference in these last two weights gives you the weight of the water 

 which ran over when the stone was immersed in the water. The 

 difference between the two weights of the stone gives the loss of 

 weight which the stone seemed to suffer upon being immersed. 

 How does this loss of weight compare with the weight of the water 

 which ran over? What is now your answer to the question: Does 

 the stone have any tendency to float when immersed in water? To 

 what extent does the water lift or hold up the stone? Repeat the 

 experiment. 



(d) Fill the pail partly full of water again. Now hold the cork 

 down near the bottom of the water and release it. What happens? 

 To what extent does the water lift, or force up, the cork? If you had 

 a body exactly as dense as water, i.e., which weighs exactly the same 

 per cubic inch, would it float or sink? What would it do? 



134. Archimedes' Principle. In performing part (c) of the 

 preceding experiment, a student got the following results: 



Weight of the stone in air 46 oz. 



Apparent weight of the stone immersed in water 30 oz. 



From which we get the loss in weight 16 oz. 



Weight of pail and water which ran over 23 oz. 



Weight of the pail empty 7 oz. 



From which we find the weight of water 16 oz. 



From this experiment the student concluded that the loss 

 of weight by the stone when immersed in water was equal to 

 the weight of the water displaced. 



This truth was first stated by a Greek philosopher named 

 Archimedes who lived about 25 years before Christ in 

 ancient Syracuse. He was a close friend of King Hiero; his 

 life was spent in the study of mathematics and science. He was 

 the most profound student of these subjects in his day. It is- 

 said that his friend, King Hiero, ordered from his goldsmith a 

 crown of pure gold. When the crown was completed, how- 

 ever, the king suspected that it was not pure gold. He 

 summoned Archimedes and instructed him to ascertain the 

 truth without injuring the crown. Archimedes was pondering 

 over this question as he went to his daily bath. Noticing, as he 

 entered the full bath, that the water was. lifted and ran over 



