THE IMPROVEMEA'T OF THE MISSISSIPPI RIVER. 705 



When this sound passes through the clounds with great power it is said to be a 

 quick, great, and dangerous kind of thunder; but when it goes through very 

 slowly it is of a weak and small kind. The ancients thought that thunder was 

 the fighting between the water and the fire in the heaven, with regard to the rule 

 of the male and female principles of nature, but this is very doubtful. If it were 

 the fighting of the water and the fire, there is no reason for there being a space 

 of time between the first thunder and the next. As it is wrought by the currency 

 of the wind and thickness of the clouds through which the thunder passes, there 

 may be the different sounds and spaces of time. The earthquake is but little 

 different from the thunder. In the time of the earthquake, spme sound is to be 

 heard underground previous to it, because it is caused by the water in the inside 

 of the earth, which was compressed for a long time by the earth-air, beginning to 

 run forth. 



The wind is said, by the ancients, to be the air which is produced from the 

 sea or mountain. This world has always wind, but there is no^ strong wind unless 

 it comes from the sea or mountains. The wind is of two kinds. One, or the 

 upper wind, runs southward and the other or lower wind runs northward. The 

 former comes from some mountains or the sea, and the latter is caused by the 

 earth-air. The snow is the vapour which rises up from the earth. When the 

 vapour which has risen up from the earth becomes frozen by the cold it falls on 

 the surface of the earth again in the form of snow. Fog is also vapour from the 

 earth. Haze is the vapour which has been mixed with smoke produced by some 

 volcano. The frost is the frozen vapour sent up from the earth. Hail is sent 

 from some mountains at certain seasons and falls on some parts of the earth. It 

 does not fall on a great area. — Japan Gazette. 



ENGINEERING. 



THE IMPROVEMENT OF THE MISSISSIPPI RIVER. 



A discussion is now going on before the House Committee on Levees and 

 Improvements of the Mississippi River, the subject being the best method of 

 preventing annual overflows and preserving a sufficient depth of water in the 

 channel for large vessels. 



The Levee Commission propose to continue the system recommended by the 

 Board of Engineers of 1875, which requires levees to be raised at Cairo to the 

 height of three feet, at Memphis and Helena seven feet, at Island No. 71 ten 

 feet, at Lake Providence eleven feet, at Vicksburg and Natchez six feet, at the 

 mouth of Red River seven feet, at Baton Rouge, Plaquemines and Donaldson- 

 ville five feet, at New Orleans four and a half feet. This work is proposed to be 



