Intelligence, fyc. 397 



Accordingly the afflux of the air towards the disks counteracts 

 the small velocity which the blast would communicate, and thus 

 prevents their separation, and may even cause them to approach 

 each other, if previously situated a small distance apart. 



This rationale commences with the assumption that the disks 

 will remain nearly parallel. That there cannot be much devia- 

 tion from parallelism must be evident, since any obliquity will 

 make the opening greater on one side than on the other ; and the 

 jet proceeding with most force towards the widest opening, will 

 increase the afflux of air upon the outer surface of the moveable 

 disk in the part where the current is strongest, and thus correct 

 the obliquity. 



The phenomenon is advantageously exhibited, when the area 

 of the tube is to that of the disk, as stated ; but were any other 

 ratio, which can be successfully employed, substituted, it would 

 not alter the explanation. 



(Communicated by Mr. Amos Doolittle.*) 

 3. Singular appearance of circles around the Moon.— On the 

 evening of the 2d of November, 1827, between the hours of sev- 

 en and eight, there appeared, around the moon.t (a little more 

 than its width in diameter,) a very luminous saffron colored light. 

 On the outer edge was a circle of bright red, which was graduated 

 into a dark purple ; around the purple was a circle of bright blue 

 which faded into a yellowish green, increasing towards the outer 

 edge, to a very vivid green. There appeared to be faint white 

 rays passing from the moon across these columns, whose circles 

 formed, around this lunar glory, a larger circle of a dark lead- 

 en color, which gave the whole a very beautiful appearance. 



It was observed by a great number of spectators at New Ha- 

 ven, who all say they never saw any thing of the kind equal to it 

 in the whole course of their lives, and some of the spectators 

 were aged people. A little girl ran in to her friends exclaiming 

 " come and see the prettiest moon that ever was." 



NOTE. — The Geological Profile which forms the frontispiece 

 of the present volume, and the pictured tablet, at pp. 144 — 5, 

 to illustrate Prof. Eaton's Geological Nomenclature, were pre- 

 sented to this Journal, by the Hon. Stephen Van Rensselaer, 

 whose liberality to the cause of useful knowledge, and whose 

 enlarged views of the primary interests of his country, entitle 

 him to its warmest thanks, and to the gratitude of posterity. 



* Mr. Doolittle, engraver to this Journal, has presented to the public the 

 annexed plate, representing this beautiful appearance, and his daughter Miss 

 Sarah Doolittle, has colored it, as she copied the hues at the moment, and 

 before they had changed or materially faded. — It is a very correct represen- 

 tation, as it was seen by the Editor among many others. 



t The moon was about two hours from its rising. 



