364 Intelligence and Miscellanies. 



outer surface not being neutralized,) will be apparent. This 

 will continue to be the case until the current becomes so 

 much expanded that the force which it exerts upon the atmos- 

 phere, just as it leaves the space between the cards, is not 

 sufficient to overcome the inward pressure of the air ; for 

 then the air will rush in and the disc (H I) will be separated 

 from the other. 



Amongst other experiments which appear favorable to the 

 preceding explanation, the two followmg are submitted to 

 your consideration. If the two cards are each about an 

 inch in diameter it will be found rather difficult to produce 

 the effect, but if the plane card remaining the same, the con- 

 cave one is one and a half or two inches in diameter it may 

 very easily be drawn towards the plane one ; if with the large 

 card we use a plane one with the same radius, but having a 

 segment cut from it, the concave disc, we shall find, will al- 

 ways have a tendency to slide over to the part where the 

 plane disc is whole. These facts determined by experiment 

 appear to be consequences of the explanation. If this should 

 meet with your approbation you will favor me by inserting it 

 in your Journal. 



The current passing towards the card (C D) on the exterior 

 side is hardly sensible, and appears far from sufficient to 

 overcome the opposite pressure. 



Yours respectfully, 



Cadet Jas. H. Taylor. 



7. Zodiacal Light, Halos, ^c. 



Remarks in a letter from Mr. David Leslie to the editor, dated New York, No- 

 vember 16th, 1828. 



Sir — To my communication in the October number of 

 your Journal, on atmospheric phenomena which I had sup- 

 posed to be what has been called Zodiacal light, an editorial 

 note appended classed those appearances under the head of 

 Halos. On reconsidering the subject I am inchned to think 

 that they are neither Zodiacal light nor Halos. Halos, I 

 believe, are always lesser circles or arCs of lesser circles, 

 whereas what I have endeavored to describe are luminous 

 triangular beams terminating in a point diametrically oppo- 

 site the sun, consequently in the plane of the zodiac and in 

 which the prismatic colors are never seen. These trian- 

 gular beams, like the Zodiacal light, form various angles at 

 their apex, are of various lengths, and have their bases to- 



