History of the Water Supply of the World / arranged in a comprehensive form from eminent authorities, containing a description of the various methods of water supply, pollution and purification of waters, and sanitary effects, with analyses of potable waters, also geology and water strata of Hamilton county, Ohio, statistics of the Ohio river, proposed water supply of Cincinnati.

by Thomas J. Bell

	PER CENT.
From mountain slopes or steep rocky hills,	80 to 90
From wooded swamp lands,	60 to 80
From undulating pasture and woodland,	50 to 70
From flat cultivated land and prairie,	45 to 60

MONTHLY EVAPORATION FROM RESERVOIR.

(From Fanning.)

	JAN.	FEB.	MAR.	APR.	MAY.	JUNE.
Mean ratio—inches	.30	.35	.50	.80	1.45	1.70

	JULY.	AUG.	SEPT.	OCT.	NOV.	DEC.
Mean ratio—inches	1.85	2.00	1.45	.75	.50	.35

AVERAGE AVAILABLE RAIN-FALL FOR STORAGE PURPOSES.

(From Fanning.)

	JAN.	FEB.	MAR.	APRIL.	MAY.	JUNE.
Gain by rain—inches	2.00	2.21	2.40	2.93	3.47	2.88
Loss by evaporation—in.	.60	.70	1.00	1.60	2.90	3.40
Difference—Gain inches	1.40	1.51	1.40	1.33	.57	—
Difference—Loss inches	—	—	—	—	—	.52

	JULY.	AUG.	SEPT.	OCT.	NOV.	DEC.	TOTAL.
Gain by rain—inches	2.99	3.00	2.67	2.53	2.48	2.24	32.
Loss by evaporation—in.	3.70	4.00	2.90	1.50	1.00	.70	24.
Difference—Gain inches	—	—	—	1.03	1.48	1.54	8.
Difference—Loss inches	.71	.80	.23	—	—	—	—

SUMMARY OF FLOW OF RAIN-FALL IN CU. FT. PER MINUTE PER SQUARE MILE.—(From Fanning.)