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niometer frequently sinks there below the freezing point ; 

 for as Mr. Traill, many years Superintendent of the garden 

 at Rhoda, informed Dr. Bromfield, " hoar frost is no 

 uncommon thing here in the winter months," and he 

 has seen ice, thin of course, formed on pools in the 

 desert. Others have informed me, that they have 

 observed the same thing, and Mr. Headland, the Super- 

 intendent of the sugar factory at Rhoda, nearly two 

 degrees above Cairo, states that the canes are occasionally 

 much injured in that latitude, 20°N., and that in January 

 sharp hoar frosts are not unfrequent, ice having been 

 formed last winter there one-fourth of an inch in thickness. 

 Even at Esne, latitude 25°N., we observed the thermometer 

 to sink to 37° F. on the night of the 20th of February, 

 1857. This, however, was during the prevalence of a 

 strong northei'ly wind, which continued for three days 

 and nights so forcibly, as to render every effort to move 

 down the river, by rowing, nearly altogether futile. But 

 in Cairo, I found in December, 1856, the temperature 

 more than once below the freezing point. On the last 

 day of that month, the temperature was, in the sim 

 maximum, 110° F., in the shade, maximum, 70° F. ; and 

 the lowest temperature at night, 46° F., there beuig a 

 slight southerly wind. 



During the winter, for the most part, the sky at Cairo is 

 clear, the air in the day dry, and the mid-day heat pleasantly 

 tempered by the northwinds ; whilst the night fogs nearly 

 always disappear soon after sunrise. It has been calculated 

 by Mr. Rhind that, " taking an average of six years, at 

 various intervals between 1762, and 1856, from the middle 

 of November until the middle of April, rain appears on 

 about fifteen days and nights, chiefly in January and 

 February ; but on the majority of these, the tall is con- 

 fined to a few drops, or some slight showers." On the 

 whole, the climate of Cairo may be safely recommended 



