82 Mr. Bond on Occultations and Eclipses. 
Month — ~ ) Imm. 
Year. and Observations. or Time. General Remurks. 
Day. Im. % | 
1831.|/Feb. 13. |Occult. of Planet Venus. "| hem. 8. The moon was not dis-| 
Immersion of the Centre,Imm.| 1 43.56 P.M.'cernible. A gradual dim-| 
Total Immersion, . . 1 44 19 inution, till at last it threw) 
out some scintillations and 
disappeared instantly. 
1831./Feb. 19. |Occult.1l¢ Tauri, . . |Imm.| 7 31 161 P.M.) Emersion appeared 
Em.| 8 44 4.6 good, but quite clear of 
the moon’s limb. 
1831.|Feb. 19. |Occult.2¢ Tauri, . . |Imm.| 7 4045 P.M. 
| Em.+ 8 36 11 
1831.|Feb. 19. |Occult. of Aldebaran, . Jmm.|!1 43 37 P. M. 
1831.|Feb. 28. |Occult. 1 » Virginis, . | Em.| 8 31 0.2 P. M.\Star rose eclipsed. 
Intending to make some experiments on the change of 
temperature, during the Solar Eclipse of February 12, 1831, I ob- 
tained one of Professor Leslie’s Differential Thermometers ; the 
scale aflixed was graduated from zero to 90°, and adjusted to stand 
at 45°, when both bulbs were of an equal temperature, in order 
that it might show, by exposing each bulb alternately to the 
solar rays, a greater range of the colored fluid. The southern 
opening in the room for the ‘Transit instrument afforded a con- 
venient situation. A Fahrenheit’s Thermometer was so placed 
that its bulb might be nearly in contact with that bulb of the 
Differential Thermometer which was in the shade. 
The hour previous to the commencement of the Eclipse, the 
atmosphere being clear, a Thermometer placed in a north 
exposure, stood at + 29°. The Differential Thermometer indi- 
cated 28 divisions of its scale in the reversed positions (that 
being the mean of six observations, the extremes differing three 
divisions from the mean) as the effect produced by the solar 
rays; and the attached Thermometer stood at + 30°. 
From 1h. 10m. to 1h. 30 m., about the time of greatest obscu- 
ration, the northern Thermometer stood at + 24°, the attached 
at + 28°, and the differential indicated one division as the 
