444 THE CHEMISTRY OF CREATION. 



mapped on paper by the combination together of 

 trigonometrical processes performed at different 

 places by various observers, and finally brought 

 together and projected on one sheet. 



Sometimes the great tidal wave, when met 

 by an opposing current from the waters of some 

 large river, raises a mass of water of great 

 height and force, called the Bore. We know 

 little of the power of this remarkable pheno- 

 menon on our coasts, although it is observable 

 in some of the rivers, such as the Severn and 

 Trent. But in India, the bore of the Ganges 

 has long had a fearful reputation. Sometimes 

 it appears as a roaring mass of many waters, 

 four or five feet high, often overwhelming with 

 destruction all the smaller craft exposed to its 

 power. In other rivers it attains a still greater 

 magnitude. But the grandest display of this 

 phenomenon is described as occurring near the 

 mouth of the great river Amazon. At the 

 ebbing of the tide this mighty stream pours 

 down at spring-tides a vast volume of water, 

 with great velocity, into the ocean. The 

 current, at a little distance from land, meets 

 with a powerful opposing oceanic current. The 

 result of this great conflict between opposing 

 waters is to raise a mighty mountain of water, 

 attaining, as it is said, the height of 180 feet, 

 which carries terror and desolation along its 



