Self-Registering Rcdn-gaiige. 13 



stretch from the increasing weight, until the vase is full, 

 when it is about two inches lower than in its empty position. 

 Immediately it is emptied by action of the siphon, the vessel 

 recovers its original position. 



The other parts are — a common clock (C), which rotates a 

 cylinder (D) about 4 inches in diameter once in 24 hours ; 

 on this drum is stretched the paper on which the register is 

 made. Attached to the vase is a fine wire running over 

 pulleys (VV) on the top of the bracket, and also attached 

 to a light brass frame (H) that has a free vertical motion 

 guided by two stretched German silver wires. As the vase, 

 therefore, descends with the accumulation of rain, this light 

 brass frame is raised by means of the fine wire. In the 

 frame is a freely -suspended glass pen, charged with an ink 

 made of aniline dye with a little glycerine. The point oi 

 this pen, which is horizontal (the surface of the registering 

 cylinder being vertical) rests lightly against the register 

 paper, and marks it with a clear fine line as the barrel 

 rotates by clockwork ; this line is straight as long as there 

 is no rain, but becomes more or less curved according 

 to the rapidity of any rainfall ; as the vase empties itself 

 the pen at once returns to the zero position, showing 

 an indentation or "tooth," as it were, on the register- 

 paper for every quarter of an inch of rain. A sheet showing 

 two inches of rainfall has therefore eight indentations or 

 " teeth" on its register, and the paper being graduated, any 

 fraction of an inch of rain less than a quarter can be read 

 off", while graduations parallel with the axis of the barrel 

 give the times of any phases of the phenomenon. 



Reference to Diagram. 



A A. Base-plate of cast iron. B. Pillar and bracket of cast iron. C. 

 Clock. D. Kegister-drum, or barrel. E. Vase-shaped receiver. F. Spiral 

 springs suspending vase. G. Pipe leading from collector to receiver. H. 

 Pen frame. J. Brackets to support base-plate. K. Pinion taking into 

 large wheel on which the drum is fitted. MM. Dust-tight cover for clock. 

 P. Pendulum-bob. SS. Syphon. YV. Pulleys for fine wire connecting 

 receiver and pen frame. 



