THE MISSISSIPPI VALLEY. 



21 



TABLE III. 



OF THE CALCULATED AND OBSERVED DISCHARGES OF THE OHIO 



RIVER AT WHEELING. 



No. of ob- 

 servations. 



Depth of water 

 on the bar at 

 Wheeling. 



Reduced depth 

 at place of ob- 

 servation, or 

 value of d. 



Velocity of cen- 

 tral current in 

 feet per hour. 



Discharge in cubic 

 feet per hour, as- 

 certained by ob- 

 servation. 



Discharg-e in cmbic 

 feet per hour, cal- 

 culated by form- 

 ula. 



1 



2.20 



3.43 



3,594 



10,158,000 



12,338,000 



2 



2.72 



3.85 



3,552 



11,268,000* 



15,487,000 



3 



3.55 



4.60 



5,890 



22,650,000t 



21,887,000 



4 



3.71 



4.75 



5,030 



20,100,0001; 



23,300,000 



5 



4.20 



5.18 



5,095 



22,270,000§ 



27,580,000 



6 



4.89 



5.85 



6,708 



33,300,000 



35,000,000 



7 



5.38 



6.31 



6,423 



34,560,000 



40,495,000 



8 



5.55 



6.48 



7,564 



41,600,000 



42,640,000 



9 



5.72 



6.65 



8,356 



47,300,000 



44,820,000 



10 



6.72 



7.65 



9,196 



60,000,000 



58,723,000 



11 



7.92 



8.82 



11,028 



83,000,000 



77,140,000 



12 



9.66 



10.51 



12,804 



118,400,000 



108,100,000 



13 



11.04 



11.84 



14,946 



156,400,000 



138,700,000 



14 



11.31 



12.10 



14,637 



154,000,000 



140,000,000 



15 



15.06 



15.74 



1 16,500 



226,000,000 



229,000,000 



16 



20.76 



2L22 



20,126 



378,000,000 



391,000,000 



17 



25.16 



25.45 



23,222 



530,000,000 



535,000,000 



18 



27.92 



28.16 



24,000 



611,000,000 



632,300,000 



19 



i 31.25 



1 



3L41 



24,644 



736,000,000 



758,300,000 



*Headwind. t Wind down stream. ^Headwind. §Headwind. 



It will be seen that there are several irregularities in this table. In two 

 instances the velocities exhibit a shght increase, although the depth, in the chan- 

 nel were diminished. In some instances the float left the thread of the stream, 

 and was consequently retarded. 



In the lower velocities the irregularities are very considerable, and were 

 caused altogether by the wind. It was almost impossible to obtain observa- 

 tions, when the water was very low, which were not disturbed by this cause. 

 The experiments, in this state of the river, consumed from two to three hours, 

 and the exposure of the float during all that time, to the shghtest breeze, 

 afiected the result materially. This could not be obviated by depressing it 

 beneath the surface of the water, for the surface of the water itself was also 

 retarded. These discrepancies are inseparable from the subject. Yet we shall 

 find, by summing up all the computed and all the observed quantities, that in the 

 aggregate they agree almost precisely. The formula represents the mean of 

 Art. 4 — 4 



