30 Book of Engineering 



trend when the hour of the midday meal 

 comes along, whilst a cold snap in March 

 will certainly have a pointed effect on con- 

 sumption. 



Yet the midday rise and fall shows 

 some strange changes at certain parts 

 of an hour, and they are explained by the 

 guide who says that, whilst there is the 

 demand for cooking just before one, there 

 is a corresponding drop at that hour from 

 the factories and offices because thousands 

 of lights necessary in basements and badly 

 built upper rooms are turned off. 



A question to the guide is, " How is the 

 current sent to the south side of the river 

 where most of it is used? ' 



" Wait and see," is the reply, and sure 

 enough the mystery is soon cleared up. 

 Barking power house has its own private 

 tunnel, driven well and deeply under the 

 great river. Down it go many serpents 

 that is the best simile perhaps for the 

 numerous rather bloated cables which worm 

 their way from north to south whilst great 

 ships pass over them. One is left wondering 



