1835.] BecquereVs Traitt Experimental, Sfc. 155 



ten, if the diameter of the wire was small ; but the action was dis- 

 tinct when the wire possessed a certain thickness. The effect of the 

 multiplier of 2000 turns was tribled. Similar phenomena occur in 

 thermo-electricity. 



To explain these facts, and others which have been observed in 

 reference to the interesting subject of induction, it has been con- 

 ceived that every electric current consists of the combination of two 

 currents, one positive and the other negative. 



Article IX. 



SCIENTIFIC INTELLIGENCE. 



I, — New Expeditions of Discovery. 

 London University, Evening Meeting, 14th January. 



Captain Maconochie opened the chair, to which he has recently 

 been appointed in this University, by delivering a lecture on the expe- 

 ditions of discovery, which are now in progress in South Africa and in 

 British Guayana. The subject is one of great interest, and attracted 

 much attention. The lecturer began by mentioning some facts with 

 regard to the Royal Geographical Society, under whose auspices the 

 travellers have started. This society he observed, was established in 

 1830, and notwithstanding the political state of distraction which 

 existed in the country at that period, was able in the course of a few 

 weeks to collect no less a sum than £ 7000, for the purposes of patro- 

 nising geographical research. It has already done a great deal. No 

 less than 4 volumes of transactions have been published by it, which 

 are full of important details. Through it the account of Lander's suc- 

 cessful descent of the Quorra, and of his discovery of the melancholy 

 end of poor Park, was first communicated to the public. The only 

 acknowledged report of Ross' recent perilous voyage was given by 

 this society, and the same observation applies to the enterprising 

 expedition of Lieut. Burnes and Dr. Gerrard across the wilds of Asia. 

 The lecturer read a passage from an address of Lieut. Burnes' des- 

 cription of his feelings at the intelligence, which he received during 

 his perilous journey, of the establishment of this society. He was 

 then with his companion at Bokhara, where a packet of newspapers 

 overtook him conveying the information. New vigour was immedi- 

 ately instilled into their adventurous spirits; as they were now 

 aware that there were some at home who sympathized with them, 

 and who, if they should perish on their route, would nobly rescue 

 their names from oblivion. 



To confer additional importance on the influence of this society, 

 his Majesty has been graciously pleased to give his countenance to 

 its labours, and has generously granted an annual premium of 50 

 guineas to be bestowed on contributors to geographical discovery. 

 Premiums have been already conferred on Lander, Ross, and Burnes. 



The society have it now in contemplation to patronise adventurers 

 in the discovery of the unknown regions of Africa and South America. 

 In the former country, with the exception of a few Portuguese 



