138 LIGHT SCIENCE FOR LEISURE HOURS. 



little damage, as it here expanded over the plain, and 

 was reduced both in depth and velocity. 



(From the Daily News for October 20, 1868.) 



A GREAT TIDAL WAVE. 



DURING the last few days anxious questionings have 

 been heard respecting the next spring tides. A certain 

 naval officer, who conceives that he can trace in the 

 relative positions of the sun and moon the secret of 

 every important change of weather, has described in 

 the columns of a contemporary the threatening signi- 

 ficance of the approaching conjunction of the sun and 

 moon. He predicts violent atmospheric disturbances ; 

 though in another place he tells us merely that the 

 conjunction is to cause ' unsettled weather,' a state of 

 matters to which we in England have become tolerably 

 well accustomed. 



But people are asking what is the actual relation 

 which is to bring about such terrible events. The 

 matter is very simple. On October 5, the moon will 

 be new in other words, if it were not for the bright- 

 ness of the sun, we should see the moon close by that 

 luminary on the heavens. "Thus the sun and moon 

 will pull with combined effect upon the waters of the 

 earth, and so cause what are called spring tides. This, 

 of course, happens at the time of every new moon, 

 but sometimes the moon exerts a more effective pull 



