﻿330 Transactions — Chemistry. 



Art. JJVll.^-On a Form of Electro-Magnetic Seismograjjh adapted for Indi- 

 cating or Registering Minute Shocks. — By W. Skey, Analyst to the 

 Geological Survey of New Zealand. 



[Read hef ore the Wellington Philosophical Society, 25th JN'ovember, 1871.]* 



The autlioi' has prepared an instrument for this purpose in which an electric 

 circuit is broken, instead of being (as in the system adopted by M. Palmieri) 

 completed by an earthquake. 



The following is a specification of this instrument : — A solid block of metal, 

 having a fine platiniini wire attached, which projects about half an inch 

 from it horizontally, is connected with a vertical galvanometer, and this with 

 a single pair or small battery of pretty constant power. 



A very fine platinum wire depends from a point above in such a position 

 that it presses slightly upon the wire just specified by its lower extremity, a 

 small bob being attached thereto to steady it. A fine screw, or other proper 

 adjusting apparatus, is employed to regulate the pressure (i.e. area of contact) 

 of these wires iipon each other ; the top of this long wire being connected 

 with the other pole of the battery. This apparatus when properly set is 

 capable of indicating very feeble shocks. A gentle wind of varying power 

 playing upon the substantial building in which it was first used kept the 

 indicator constantly in motion. When the shock receiving part of the instru- 

 ment (a massive pile of wood bearing the metal block), in order to avoid efiects 

 of wind, was placed under ground, it was ascertained that the impact of two 

 pounds weight of stone, falling from a height of five feet upon ground situated 

 fifty feet from this part of the instrument, affected the indicator very detei'mi- 

 nately. The intervening groiind was clay. In conclusion, the author des- 

 cribes the method in which he arranges a series of such shock-receivers, with 

 batteries for denoting direction of shake, so as to secure economy with efiective- 

 ness, and by which constancy in battery power can be dispensed with. 



Art. LYIII. — N^ew Process for the Manufactwre of Sulpho-cyanide of 



Potassium. 

 By W. Skey, Analyst to the Geological Survey of New Zealand. 



[Read hefore the Wellington Philosophical Society, 2hth November, 1871.] 



The methods by which this salt is now prepared for laboratory and other 

 piirposes necessitates several purifying processes, in oi'der that the ultimate 



* Tte original paper, of which this is an abstract, was sent to the Editor of the 



" Chemical News. " 



