River Temperature. 43 
TABLE IV. 
Analysis of Various Observations to Illustrate the Crossing 
of the Air and Water Temperatures in Winter in the 
Lower Nile. 
| January. Dec.-Jan. Feb. | 
Locality. _—__— | 
Chaix. |Schnepp| . ate Hay. Mean. Stuart. Stuart. 
Cairo | Air, He0' |! b6- h bag |: 552 65:7 63°4 | 
to Wis ters |659°95 19 600 5798) |" ty cee os 59°3 66°5 64°6 
Thebes. | W.diff.} +4:°9) +39 |)4384]  ...... +4:1 +0°8 +12 
Thebes | Air, Die, Ol: | 6553 61°6 61°5 C2Et |) cases 
to Water, | 60°3 | 61°9 | 63°5 60°6 61°6 65°0 | 
Assouan, | W.diff.| +2°9 | +04 | -1°8 -1:0 +0°1 HB haltaeadces | 
Phile | Air, 66°1| Kalabshi | Air, 60°6 
to Water, 6271 to Water, 59°4 
Kardaseh, | W.diff. - 4°0| Abu Simbel. | W. diff. — 1-2) 
TABLE V. 
Analysis of the Observations made by Mr Villiers Stuart 
during his Ascent of the Nile from Cairo to Abu Simbel, 
December 6, 1878, to January 10, 1879. 
Air Means. Difference of | Mean excess 
a Water | the Water | of the Wate 
Month, Locality. Mean. |Mean fromthe} Temp. at : 
| Min. | Max. | Mean. Air Mean. Sunrise. 
Dec. 6-13 | Cairo to Beni Hassan, 57-8 | 74°6 | 66-2 | 66"5 +0°3 8:2 
,, 14-22 | Beni Hassan to Keneh, . | 56°4 | 74°0 | 65°2 | 66°5 +1:3 9°6 
,, 23-31 | Keneh to Kardaseh, . | 53°8 | 71°1 | 62°4 | 64°6 +22 10°3 
Jan. 1-10 | Kalabshi to Abu Simbel, | 54°3 | 67°0 | 60°6 | 59°4 —1°2 4°7 
Note.—The air mean is the mean of the minimum and maximum observa- 
tions. The water mean is the mean of the sunrise observations, plus half 
a degree to allow for the daily range, as indicated by the data of Hay, 
Marcet, and others. The last column is intended to serve as a check, 
Knowing the daily air range, and the difference between the air and water 
at sunrise, we can at once roughly determine the relative position of the air 
and water means, 
