EXCURSIONS AND EXAMINATIONS 247 



The barometer is placed by the side of some mountain, and in this man- 

 ner they calculate taking the readings from the barometer. 



(4) The ocean contains poles, insects live at the bottom of the ocean 

 and bore holes in the poles, when the poles are reached they reach the 

 bottom of the ocean. 



(5) The depth of the ocean is determined because it is always mov- 

 ing and wearing away the bottom. 



(6) The depth of the ocean is determined by fixing a piece of rope to 

 a heavy piece of metal which is lowered into the water, and as soon 

 as it touches the bottom the weight is no longer felt and the rope is 

 cut off at the surface of the water; the rope is then measured. It is 

 brought up by a diver. 



(7) The depth of the ocean is determined by sounding or pianoforte 

 wire which is let down until it reaches the bottom of the ocean; great 

 care must be taken to catch the sound. 



Equally gross ignorance is shown as to the mariner's com- 

 pass, the question being whether it always points due north, 

 if not, why not? 



(1) The mariner's compass do not always point due north because if 

 it did on board a ship, the captain of the ship would want to go south 

 and it would guide him the wrong way, instead of south it would guide 

 him north, so it is made to turn N.S.E.W. The mariner's compass is 

 made to turn round in any way in which the captain wishes to turn it, 

 so as to guide him which way he wants to go. If he wants to go to the 

 south he puts the point to the south, etc. They are used by men who 

 want to go to different parts of the world. Say if a man is lost in trav- 

 elling to Germany he looks at his compass, and if it is north he puts the 

 point north, or if it is south, etc. 



(2) The mariner's compass does not point due north because the 

 wind affects it. If the wind is blowing hard the dial points slightly to 

 the north, and when it is a heavy storm the dial points nowhere, but 

 just swings backwards and forwards. 



Another subject of the greatest interest and one that can 

 be very easily taught to even young children by a number of 

 simple and easy experiments, is that of the weight and 

 density of the atmosphere, and the construction of the 

 barometer. Some knowledge of these subjects is essential to 

 a clear understanding of a great number of natural phe- 

 nomena. Yet this is how, so late as 1889, some of these 

 students replied to easy questions about it :— 



