217 
1SG1.] Bote on the Bain-Fall in the Mahanuddy Basin. 
rain storm is required to ensure rain falling on every square inch of 
its area simultaneously ; again, the form of the basin is that of an 
extremely round and compact body with a narrow neck and bell-shaped 
mouth ; than which form it is difficult to conceive one (short of a 
geometrically perfect one) more calculated to empty itself rapidly— 
and it appears lastly, that th e position is one of very close proximity 
to the sea, the source of rain clouds. With these pre-eminent quali- 
fications for filling and rapidly emptying itself, engendered by form 
and position with its size being so limited as to leave no doubt but 
that a large rain storm may at once and the same time fall upon 
every square inch of the basin, with steep and densely wooded moun- 
tains encircling it, and with steep rocky slopes covering its area, I 
think it must be allowed that the Mahanuddy Basin is pre-eminently 
calculated to produce what are actually met with, floods ranging ex- 
tremely high, but of very brief duration. 
I will dispose of the second point proposed above by offering the sub- 
joined questions for solution and going into the calculations necessary. 
Question 1.— How many inches of rain must have fallen over the 
whole area of the Mahanuddy Basin above the Delta (the rain in 
the Delta was very insignificant) to have produced the great flood of 
the 29th July, 1855 ? 
Solution 1.— This extraordinary flood commenced to rise at Cuttack 
at about 9 a. m. on the 27th July ; at which time the river gauges 
stood (as they had done for several days previously) as follows : 
Kaporee, 18 feet* 
Mahanuddy, 23 „ 
and the flood subsided to these guage levels by the 2nd August. 
During this period of seven days the discharges of the two arms of 
the Mahanuddy were as below; vide Report Part III. Cuttack Rivers’ 
Survey, page 25. 
In the Mahanuddy, Cubic feet 410,701,819,200 
„ Kajoorce, „ 351,007,824,000 
761,772,043,200 
* Neglecting small decimals. 
