314 Electrical Phcetwmena. — Longitude, — Safety -lamp, 



there is a certain number of tubes, which alternately radiate or 

 turn in towards the centre, rendering the moving power at one 

 time strong, at another weak ; but preserving throughout such 

 an intensitv of force, that it is necessary to keep it in check by 

 a regulator. ■ — 



ELECTRICAL PHiENOMENA. 



On the evening of the 11 th March a very uncommon electrical 

 phaenomenon appeared at Belfast, at intervals, between seven and 

 eleven o'clock, nearly due west. Its general shape was that of 

 a comet, but much larger, with its tail upwards; \x.^ micleus 

 might be about four or five degrees in diameter, and thirty de- 

 grees from the horizon ; but although its shape, size, and inten- 

 sity of light were constantly varying, its position remained nearly 

 the same. It was now and then accompanied by flashes of 

 lightning. The evening was dark, rainy, and stormy. 



A letter from Corsica of the 3d April says, " For three months 

 We have had no rain, and the most incessant and terrible winds 

 have prevailed. In the middle of March a dreadful conflagration 

 appeared in the canton of Venaco ; in less than three hours the 

 flames had destroyed a surface of more than two leagues of this 

 fine country. Fifteen houses were burnt in the village of Poggio. 

 It is believed that the cause of this fire was electrical, and that 

 fires of a similar kind that have happened in other cantons had 

 the same origin." ' ■ 



LONGITUDE. 



Mr. David Christieson, teacher in Montrose, is said to have 

 discovered an easy and exact method, by which tlie iongitudo. 

 may be ascertained in any part of the world, either by land or 

 sea, by means of a meridian altitude of the sun. ' It is pointed 

 out by a very simple instrument, constructed on mathematical 

 principles, and does not require those tedious calculations from 

 solar or lunar tables, by which the ordinary method becomes fre- 

 quently liable to such uncertainty. Neither does it depend on 

 time-keepers, which, though brought to great perfection, cannot 

 be implicitly relied on, especially in long voyages, or where the 

 variations of heat and cold may alter the regular motion of these 

 delicate instruments. 



SAFETY LAMP. 



M. Van Mons has sent us the gratifying intelligence, that the 

 safety lamp of Davy has completely succeeded in the Netherlands. 

 *' Fortified with it," he says, " we can penetrate into the foulest 

 mines. We have even opened depots of gas, and procured its 

 mixture with the proportion of atmospheric air calculated to pro- 

 duce the most prompt inflammation, and the strongest explo-. 



