May S, 1885.] 



SCIENCE. 



391 



Zambezi and the coast south of Lake Bangweolo, and 

 it is to be of a purely scientific character. 



— The German bark Ceylon reports that April 10, 

 in latitude 31° north, longitude 71° west, she was 

 struck by a water-spout, carrying away main and 

 mizzen masts close to the deck, killing the first officer, 

 and seriously injuring Capt. Newman. During the 

 early part of the night, two distant thunder-storms 

 crossed the sky. All sail was furled except reefed 

 lower topsails. Near midnight a low cloud was ob- 

 served about five degrees above the horizon. The 

 remainder of the sky was clear. The ship was head- 

 ing north-north-west, and a gentle breeze was blowing 

 from south-west. Suddenly, through the darkness, 

 something that at first seemed 

 a ship was seen quite near, 

 bearing west -north -west. 

 Then all crouched to the deck, 

 for a water-spout was close 

 aboard. The wind struck the 

 bow with hurricane force, 

 while at the wheel aft it be- 

 came a dead calm. The vessel 

 was thrown over to starboard 

 until the lower yard-arms al- 

 most touched the water. Her 

 head was forced round from 

 north - north - west to south- 

 south-east, and the sails torn 

 into ribbons. Then, as the 

 wind came round to starboard, 

 the vessel righted and went 

 over to port, until the rail was 

 under water in almost an in- 

 stant. The main and mizzen 

 masts were whipped out of 

 her, and the men thrown 

 across the deck, killing the 

 mate. Then suddenly it be- 

 came calm, and the vessel 

 righted. The captain thinks 

 it all occurred within two or 

 three minutes. During the 

 time they were in the influ- 

 ence of the water-spout, there 

 was a great deal of St. Elmo's 

 fire on all the ironwork of the 

 vessel. 



— A brief paper by J. A. Ockerson of St. Louis, 

 on the earlier floods of the lower Mississippi, in 

 the Journal of the Association of engineering societies 

 for January last, and a discussion of it by R. E. 

 McMath, furnish some interesting statements about 

 the great river. The conclusion is reached by the 

 first-named author, that, on account of the relation 

 that must exist between mean flood height and the 

 altitude of the flood plain, it is possible to conclude 

 from the equality of height of the actual and long- 

 abandoned river-banks that there has been no percep- 

 tible change in the mean flood height for at least two 

 centuries, and hence that the cutting-away of our 

 forests has not yet had a perceptible effect in the 

 ri'jime of the river. The second author justly re- 



marks that the exceptional floods may now be higher 

 than formerly without significantly affecting the 

 mean height of floods. The old river-banks alluded 

 to are now seen enclosing the crescent-shaped lakes, 

 so characteristic of rivers that shift their course in 

 alluvial plains; and these are well illustrated in a 

 plate, here copied in part (the main stream is left un- 

 shaded), constructed from manuscript maps of the 

 government surveys of 1882 and 1883, of which we 

 are glad to have even this small glimpse. Lake 

 Bruin was cut off before the river was known to 

 navigators; Lake St. Joseph was abandoned probably 

 before 1700, and in the change the river-course was 

 shortened twenty miles or more ; Palmyra Lake was 



ST JOSEPH 



MAP OF OLD RIVER LAKES ALONG THE MISSISSIPPI RIVER. 



formed by the Davis cut-off in 1867 ; it is nineteen 

 miles around, while the neck was less than a mile 

 wide. The slope of the flood plain away from the 

 immediate river-banks, caused by the quick deposit 

 of much sediment near the main channel during 

 overflows, is sometimes very marked. It generally 

 gives a lateral descent of from one to ten feet in a 

 mile, and in an extreme case the fall was 13 feet in 

 657. The bluffs enclosing the river-bottom are shown 

 on the east, but are not included on the west. 



— In the report of the International commission of 

 the Suez Canal, says the Electrical review, attention 

 is drawn to the important question of night naviga- 

 tion in the canal by means of the electric light. This 

 subject is said to be under serious consideration, ex- 



