Miscellanies. 171 



2. Whether it appears to be projected on the moon's disc, and if 

 so, for how long a time. 



3. Whether the dark limb of the moon be distinctly visible and 

 well defined at the time of the phenomenon. 



4. Whether the star on its em_ersion, appears on the moon's disc, 

 or emerges quite clear of the moon's border. 



At the time of the occultation of Aldebaran on the 16th inst. I 

 could not discover any change either of hght, color, or motion on the 

 approach of the star to the edge of the moon, except that the rays 

 proceeding from the star appeared to have a tremulous motion 

 about the time of immediate contact. The star appeared to be in 

 contact with the edge of the moon about two or three seconds be- 

 fore its total disappearance. The time of total disappearance I took 

 for the time of immersion. From the time the star appeared to 

 have come in contact with the moon until it wholly disappeared, 

 which was about two or three seconds, the star evidently appeared 

 projected on the moon's disc. This however was not so much the 

 appearance of a real star, as it was of a few bright rays that seemed 

 to diverge from the point of contact. In seeking for an explanation 

 of this phenomenon, I placed at about two feet from the eye, a small 

 sparkUng object, which gave something of the appearance of a star, 

 then by bringing the edge of an opaque object between the eye and 

 the luminous point, so as just to intercept the rays proceeding from 

 the latter to the eye, about one half of the sparkling object seemed 

 projected on the opaque body, and presented an appearance very 

 much resembling the projection of the star on the moon's disc at the 

 time of occultation. May not the appearances in both cases proceed 

 from the same cause ? 



The dark limb of the moon was distinctly visible during the great- 

 er part of the time the star was concealed, until about the time of 

 emersion, when the sun approaching near the horizon prevented it 

 from being seen. An accidental movement at the time of emersion 

 prevented me from noting the precise time of the star's reappear- 

 ing, hence in obtaining the longitude, only the time of immersion 

 could be depended on. 



The time of immersion was at 4h. 6', 17'' apparent time, A. M. 

 the longitude of the moon thence deduced was 66°, 36', 11,3" 

 which compared with the same longitude in the Nautical Almanack, 

 gave for the longitude of Nashville 6h. 47', 27" in time, which 

 agrees very nearly with the mean result of a considerable number 

 of observations of Jupiter's satelites. 



