Remarks on the Formation of Fogs. 



43 



Date of 



observations. 



CI 



0) o .. 



Hi ! 



46° 



£ •_ » 



c; 'Z ~ 



53. 



^ — - £ 



..'fee — 



u "- <— 



£ t " o 



£ - w <T. w 



| 



c 



c" c 



E u 



t- - 



1 



•- - 

 X ~ 



"si" 



li 



** 



1842, 



Jatrry 11, 





10 A. M. 



1841, 



Feb'y 15, 



49. 



59. 







10 A. M. 



it 



" 25, 



50. 



57. 







11a. m. 



1840, 



March 27, 



53. 



61.25 



61.75 



62.25 



3 P. M. 



u 



M 29, 



53. i 



60. 



60.50 



61. 



11 A. M. 



1841, 



April 1, 



56.50 



61.50 







Night 



it 



" 2, 



56.50 



64. 







3 P. M. 



li 



" 5, 



56.50 



63.50 



63.75 



64.25 



Night. 



cc 



« 19, 



57. 



71. 







10 A. M. 



1842, 



" 13, 



54. 



66. 







11 A. M. 



u 



u 27, 



55. 



59.50 







9 A. M. 



CC 



!* 28, 



55. 



63. 







Night. 



CC 



May 3, 



61.50 



67. 







Night. 



u 



" 5, 



61.50 



70. 







11 A. M. 



cc 



" 13, 



61.75 



67.50 







Night. 



cc 



« 16, 



61.75 



74. 







2 P. M. 



1841, 



June 19, 



69. 



76. 







10 A. M. 



In one of the cases referred to in this table, the opportunities 

 for making the observations were so favorable, the results so sat- 

 isfactory, and the nature and variety of the phenomena so char- 

 acteristic of the particular kind of fogs, that I will give a detailed 

 account of the observations. 



On the 27th of March, 1840, I was at the house of a friend, 

 who lives on the bank of the Mississippi River. The weather 

 was cloudy and rather cool for the season in this climate, the 

 thermometer ranging from 55° to 65° Fahr., though it had ranged 

 during some time previous at from 65° to 75°. The house was 

 situated on the eastern bank, at the distance of about four hun- 

 dred yards from the water's edge, the greater part of the distance 

 intervening being a level plain, elevated at the time of observa- 

 tion only a few feet above the level of the water, then at a high 



stage ; but near the house the land rises abruptly, forming a bluff 



about fifty or sixty feet in height, and on this bluff, near the de- 

 clivity, the house is situated. 



About noon there was a light shower of rain, and it remained 

 cloudy during the remainder of the day. At 3 o'clock, p. m., 

 being on the gallery, which commanded a view of the river, I 



