212 Wisconsin Academy of Sciences, Arts, and Letters. 



has suggested the idea, to some of our geographers, of joiniog the 

 continents and assuming lines of cleavage. 



South America, Africa and Oceanica have a strong resemblance ; 

 the locations of such detached portions as the Falkland Islands, 

 Madagascar, New Zsaland, Cejlon and Formosa are notable; the 

 Fjords of Norway and Patagonia and the Firths of Scotland re- 

 semble each other closely, while the serrated S. W. coa?t of Ire- 

 land is the duplicate of the to coast of Maine. In these localities 

 the tide impinges upon the coast in the same manner, in each case, 

 both as to direction and impulse. 



^ We may further observe the work of eroeion of the average tide 

 and of the greater at maximum declinations in the double in- 

 dented coasts on the west of the continents, the first impulse of 

 the tiie being frooi west to east in nearly all cases. 



According to the usually accepted theory of the tides, the 

 moon elevates the water of the ocean by attraction. Now, if we 

 admit of attraction, we must also admit of its laws according to 

 one of which, bodies attract with a force in direct proportion to 

 their masses. The mass of the sun is such that his attraction 

 upon the earth is 170 times greater than the moon's and the tide 

 should be in proportion to the respective attractive powers of the 

 two bodies. 



Eeclus in "The Ocean" says that, " the solar tides would be 

 5000-6000 feet high if the true cause of the tides was not to be 

 found in the difference of attraction exercised on the waters of 

 the different parts of the earth." The difference of the moon's 

 attraction on the near and remote sides of the earth is just twice 

 the difference of the sun's, while the sun's attraction is 589 mil- 

 lionths of the earth's gravity and moon's attraction is only 3-4|- 

 millionths. The centrifugal force at the equator due to the earth's 

 rotation is the l-289th part of the earth's gravity and hence only 

 six times greater than the sun's attraction, while it is more than 

 1000 times greater than the moon's. 



The moon's assumed affinity for aqueous matter we will not 

 consider since we have as yet no reason to doubt that gravitation 

 is the same throughout the Universe. In space, all matter is at- 

 tracted alike, that some bodies are heavier than others is that they, 



