12 H. J. Harman— Operations for obtaining [Noxd; 
Before commencing work I sent men to see the channel and they reported 
it shallower than it was in the preceding year: just before closing work 
I found that at the village C the channel was wide, breast deep and the 
flow slow. To allow for this unmeasured percolation through the sands 
I have added to the measured discharge of the Brahmaputra 3000 cubie feet 
per second to bring the result nearer the truth. The “ Buri Suti” channel 
for two miles from its mouth has no water in it, but at 15 miles from its 
mouth it is rarely fordable. 
After the work was finished on March 19th there was a rise of 6 feet in 
the river, and at Gauhati on March 24th it caused the gauge register to 
read 4.6 ft. above the zero, 
For the section, 120 soundings were taken: observations for velocity 
were made at 14 stations, and there were 255 recorded passages of the 
floating instruments. 
The resulting discharge at the low level of the year was found to be 
118,115 cubic feet per second ; the superficial area of section was 24,477 
superficial feet, so that the mean velocity of the water was 4.6 feet per 
second. ‘To the observed diseharge, 8,000 cubic feet must be added for 
percolation through the sands and flow through the channel D, mentioned 
above, thus bringing the discharge up to 116,115 cubic feet per second. 
During very high floods the water rises 20 feet, but calculations have 
been made for an ordinary high flood rise of 16 feet, which gives a dis- 
charge exceeding 830,000 cubic feet per second, a sectional area of 164,000 
superficial feet, so that the mean velocity of the flood is 5 feet per 
second. 
For an extreme flood the discharge would exceed 1,100,000 cubic feet 
per second, and the sectional area 208,000 superficial feet. Fora rise of 3 
feet over the low level of the year, the increased section would be 14,100 
superficial feet and the increased discharge 54,000 cubic feet per second. 
The next river measured was the united stream of the Dihang and 
Dibang rivers, at one mile above the junction with the Brahmaputra and 
one mile below the mouth of the Dibang river. At the time of measure- 
ment the river was somewhat less than 3 feet above the low level of the 
year. 
The weather was fairly:favourable and the site selected was a good 
one. The work was done between March 24th and 27th of 1878. 
For the section, 59 soundings were taken, observations for velocity were 
made at 12 stations, and there were 170 recorded passages of floating in- 
struments. 
The resulting discharge was 110,011 cubic feet per second, sectional 
area 25,105 superficial feet, so that the mean velocity was 4°4 feet per 
second, 
