394 Tables for determining Heights [No. 5. 



come from the direction of Lica, on the Indus, to the west and by south 

 of Lahore, and to have a north-easterly direction. An officer travelling, 

 and at the distance of twenty miles or so from Lica, was suddenly 

 caught in it ; his tent was blown away, and he himself knocked down 

 and nearly suffocated by the sand. He stated to me that he was 

 informed by one resident at Lica, that so great was its force at the 

 latter place, as to crack tbe walls of a substantial brick dwelling in 

 which the above officer had lately resided, and to uproot some trees 

 about. 



The instant the insulated wire is involved in the electric current 

 marked by the column of dust, down streams the electricity. 



I have sometimes attempted to test the kind of electricity, and find 

 that it is not invariably in the same state ; sometimes appearing +, at 

 other times -, and changing during the storm. 



One day I caused the current to pass through a solution of cyanide 

 of silver, so as to affect a small piece of copper, which was rapidly co- 

 vered with a coating of silver, which upon drying peeled off. In this 

 case the cyanide of silver was pure, without any salt ; but in subse- 

 quent attempts to silver a wire in this way, I have not succeeded, only 

 a very slight deposit taking place, which was not increased by long 

 exposure to the influence. 



But in all the cases I tried subsequent to the one first alluded to, the 

 oxide of silver was dissolved in cyanide of potassium. In the course of 

 time bright and minute crystals were formed, transparent and colour- 

 less, on a copper coin. Yours truly, 



P. Baddeley, 



Arty. Surgeon, Lahore. 



Tables for determining Heights by the Barometer. Computed by 

 Major J. C. Hannyngton, B. N. I. 



These tables are so framed as to bring the logarithmic process into 

 a purely arithmetical and very simple form. 



They are to be used as follows : 



Rule. Correct the Barometer at the colder station, by adding the 

 correction from Table I. fur the difference of temperature. 



