486 SCIENTIFIC RECORD FOR 1885. 



lever, whose long arm touches a strip of paper covered with a film of 

 iodized starch. This paper is carried by clock-work beneath the point, 

 and every five minutes the clock sends a galvanic current throi/gh the 

 pointer and leaves a dot upon the starch film. On examining the rec- 

 ords thus made he finds (1) sometimes for days the i^ointers are. station- 

 ary; (2) sometimes they are in a state of tremor, which may continue 

 for ten or twelve hours, and the sparks mark the paper at many jioints 

 in a band several millimeters wide; (3) sometimes the pointer will slowly 

 wander from the straight line and then return, but the author is not yet 

 certain whether this last is due to a slow earth tip or to local causes. 

 The delicate instrumental observations proposed to be made in the 

 Takashima mine were found impracticable, and it was then proposed to 

 remove the instruments elsewhere. 



K. Sekiya has described a form of Ewiug's duplex pendulum seis- 

 luometer, which it is stated can be made at a cost of only about $0, and 

 which gives indications agreeing very well with those obtained from the 

 more elaborate instrument. {Trans. Seis. Soc. of Japan, viii: 83.) 



JDr. F. Du Bois has translated from a paper received from F. Faura, 

 of Manila, a description of the Cecchi seismograph constructed for the 

 observatory there. The apparatus is attached to the perpendicular face 

 of a marble slab, and consists of a clock, a vertical pendulum, several 

 weights suspended bj' sj>rings, and a moving sheet of smoked paper. 

 The whole is so arranged by a combination of levers and strings that 

 any motion, either horizontal or vertical, will start the clock and will 

 put in motion the smoked i)aper, on which the vertical pendulum re- 

 cords its vibrations, as does also a spring-suspended weight. The 

 arrangement is comi^licated, needs a number of delicate adjustments, 

 ujust necessarily be expensive, and finally must be entirely reset through- 

 out after every shock. {Trans. Seis. Soc. of Japan, viii : 90.) 



A novel seismograph is described by M. Cordenons in La Xature i: 

 237. It is intended to record the vertical and horizontal shocks, 

 their duration, and the time of the initial shock. It consists of two 

 horizontal pendulums to mark vertical motions, and four inverted pen- 

 dulums, each of which last is free to fall only in one direction, the four 

 motions being directed along the four sides of a square, so that only 

 that one will fall which is in the direction of the earth's, motion. The 

 fall of any one of the i)eudulums suffices by a system of cords to release 

 a clock pendulum previously fastened out of the perpendicular, and so 

 to start the clock. When once the arrival of an earthquake shock has 

 been signaled by the motion of some pendulum, no further record is 

 possible until the instrument is reset. It is therefore a seismoscope 

 rather than a seismograi>h. 



W. Werner has given to German readers a good account of the re- 

 cent appliances for the instrumental observation of earthquakes, the 

 material for which is mostly drawn from Ewiug's memoir on Earthquake 

 Measurement. {Zeitschr.fiir Instrmnentenlcunde, v: 217,308.) 



