March 17, 1879. 



Chas. Speck in the chair. Ten members present. 



Mr. Chas. M.Scott read a paper on "Plans of Improvement of 

 Western Rivers." This paper was referred to the Publication 

 Committee. 



Mr. Nipher described a new device for the projection of pen- 

 dulum figures while forming. 



The bob of the pendulum consists of an iron ring {rr^ about 20 inches 

 in diameter, and weighing 25 or 30 lbs. From opposite extremities of a 

 diameter, metal rods (rZ») pass upwards to a cross-bar 

 (35), from the middle of which the pendulum is suspended 

 on a single wire, or chain. In order to obtain vibrations 

 of various kinds, this single wire may be made to branch 

 into two wires at any desired point, in the usual manner. 

 Passing through the iron ring at opposite points are two 

 long screws, the inner ends of which are connected by a 

 small wire, swivels being introduced in such a way that 

 the wire can be stretched without twisting. The middle 

 point of the wire bears a stylus, the lower extremity of 

 which rests upon a blackened glass. This glass, which is 

 directly over the condensing lens of a vertical lantern, is carried upon 

 a ring provided with a vertical rack and pinion movement, so that the 

 tracing can be stopped at any moment by lowering the slide. The bar {bb) 

 should of course be far enough above the ring to accoinmodate the focus- 

 ing lens and the mirror which reflects the beam of light to a vertical 

 screen. With a pendulum 15 ft. in length, the effect on the screen becomes 

 very striking and impressive. 



Afril 7, 1879. 



A. Todd, Vice President, in the chair. Eight members present. 



In behalf of Chas. M. Scott, the Corresponding Secretary pre- 

 sented a detailed map of the Mississippi River. 



Mr. Nipher stated that during the last month the thunderstorms 

 in Missouri had been most frequent along the rivers Mississippi 

 and Missouri, and upon the high region running from St. Louis 

 to the southwestern part of the State. This distribution was quite 

 marked. These storms were all feeble and local, and it was ob- 

 served that local peculiarities of surface might well have a more 

 marked effect under such circumstances. 



