70 



land, would point to a great source of the desiccation of the 

 canal, as also the fact that a higher humidity of G7'G occurs 

 in October, with the lesser density then of the water of 

 10345. 



In the absence of observations for the remaining seven 

 months of the year, and of sufficient records of the winds, 

 rains, and currents on the canal, it would be premature to 

 attempt to define the real causes of the alterations in the 

 condition of the canal water at different periods of the year. 



It may, however, be surmised that there does not appear 

 to be any correspondence between the climate of the land and 

 that of the canal which passes through it, and that the latter 

 rather influences the former, and (tarries additional heat and 

 moisture to be radiated and dissipated through the other in 

 the vicinity. 



The Sweet or Nile Water Canal also runs alongside the salt 

 water one, but there are no records, as yet, of temperatures 

 or specific gravities, or whether they are different at dif- 

 ferent times of the year, as those of the other are shown to 

 be. There is no doubt but it would bring additional river 

 water and air moisture to the line of the canal, and react 

 more or less upon the latter according as the periods of the 

 flooding or ebbing of the river Nile would fill it more or 

 less with fresh water. 



It should also be repeated that the variations in the den- 

 sity of the canal waters do not appear to be dependent on 

 the variations of temperature in the outside seas, as in that 

 ease they would be highest in summer and lowest in 

 winter. On the other hand, they are of higher degree of 

 density in the spring months, and lower in the autumn 

 months, so that it is likely that the cause may probably 

 have to be sought for in the physical conditions of the canal 

 itself, irrespective of the climate of the isthmus of Suez or 

 of that of the adjacent seas. 



