446 Miscellaneous Intelligence, 



John in gum-lac, and called by him the principle of lac. This is 

 formed in large quantity when a solution of gum-lac in alkali is 

 precipitated by chlorine. — Aiinaleii der Physik. 



4. A Lightning Stroke at Sea. — On Friday, September 7th, at half- 

 past one o'clock, the Dart steam-boat, ])assing through the water at 

 about thirteen miles per hour on the five fathom channel, opposite 

 Whitstable, running for Margate, was overtaken by a stiff squall 

 from the west, with heavy rain. Several claps of thunder had been 

 previously heard. After the squall had lasted a few minutes, and 

 curled up the sea in a curious manner in patches, the denser part 

 of the cloud seemed to settle down towards the vessel. Whilst 

 noticing its proximity, Jirst a very faint illuminating light waved 

 over the starboard paddle-box, and immediately a strong flash and 

 burst took place about nine or ten feet from the deck, directly 

 between, although a little higher than the paddle-boxes. The noise 

 of the explosion somewhat resembled the discharge of a large 

 howitzer when close to the hearer, having in addition a hissing noise 

 like a Congreve rocket, yet of shorter duration. The form and 

 appearance of the fire was that of a flash from a twelve or fourteen 

 inch mortar seen at night, accompanied by some thirty or forty red 

 sparks,* like those from red hot iron when struck on the anvil. 

 The flash, sparks, and hissing, seemed to go over the larboard 

 paddle-box towards the sea. One of the seamen on the lookout 

 near the head of the vessel was thrown forward, bent, as he ex- 

 pressed it, to the deck. Two others near him received violent 

 blows on the legs, all which, I have no doubt, arose from the sud- 

 den expansion of the air,t indeed the expansion sensibly shook the 

 whole vessel, and the passengers on the aft part of the deck felt 

 the heat in their faces* from the flash. Luckily the rain had driven 

 the passengers from the fore deck either into the cabins or under 

 the awning of the after deck. — Maidstone Journal. 



5. Height of the Aitrora Borealis. — From a comparison and 

 consideration of numerous observations relative to several zones of 

 light similar to that which appeared in so striking a manner on the 

 evening of the 29th of September, Mr. Dalton concludes that 

 these luminous arches of the aurora which occasionally appear 

 stretching from east to west are all of the same height, and that 

 height about one hundred miles. As to the height of beams, there 

 are no observations from which that may be determined. — Vliil. 

 Mag. N. S. iv. 428. 



6. Aurora Borealis. — An aurora borealis was seen from North 

 End, Hampstead, near London, from about seven o'clock until 



• These two facts would seem to imply tiiat a part of the iron of the chimney 

 or some other substance had been momentarily inflamed by the lightning. It is not 

 probable that either of the effects depended directly upon the pure electricity. — l^n. 



f More probably from what is usually designated as the returning stroke by 

 electricians. — Ed. 



