482 Note on the Discharge of Water, by the Irrawaddy. [No. 5. 



above Ava, without observing any perceptible difference or diminu- 

 tion of size. 



Under these circumstances, discoveries of much interest may be 

 expected to result from an investigation of the source of the Irra- 

 waddy. 



It is true that a part of the Chinese province of Yunnan ap- 

 proaches to within four days journey of Mogoung, and presents an 

 extended boundary along the north-eastern frontier of Burmah 

 sufficient to account for the direct intercourse that appears to be 

 carried on between the two nations. But Yunnan itself seems to be 

 here a mountain province, with perhaps but little communication 

 with the rest of the Empire. 



If on the other hand, the Irrawaddy be found, as is not unlikely, 

 to be the continuation of one or other of the two great rivers laid 

 down on Pemberton's Map as coming from the north of Thibet, 

 some great gate or pass may be found across the chain by means of 

 which an easy communication is formed with the central provinces 

 of China. 



The mean depth of the river on the 25th of April was ascertained 

 to be 12.70833. 



The mean speed of current was found to be If \ of a mile or 

 3440 yards per hour. 



The mean speed multiplied by 0.8 will give the average speed of 

 the whole volume. The direct breadth of the Eiver opposite the 

 Commissariat Grhaut, taken by means of the Theodolite, was found 

 to be 1210 yards. 



Average speed in feet. Mean depth. Breadth in feet. 



8256 X 12.70833 * 3630 = 



380,859,500.1024 cubic feet discharged per hour. 



380,859,500.1024 _ 6 347 658>3 3 504cubic f eet discharged per minute. 

 60. & i 



6347658.33504. 1n ^ 0/)Qnrrc . ;: f \ -,. , -, -. 

 =105794. 3Q55S4 cubic leet discharged per second. 



There are 6.2321 gallons in a cubic foot. 





